The Size of Persian Armies

[Lord Oda Nobunaga]

The Persians at Gaugamela

Generally the Achaemenid army is considered to have been an absolutely massive force comprised of all the peoples and tribes of the Persian Empire. Ancient writers ascribed to the Persians incredible numbers. For the Battle of Gaugamela Arrian claimed 1 million infantry and 40,000 cavalry, Diodorus Siculus 800,000 infantry and 200,000 cavalry, Plutarch a round sum of 1 million soldiers, Curtius Rufus 200,000 infantry and 45,000 cavalry. In the past century more accurate figures were attempted. Peter Green suggests 100,000 at most in his book in 1990. John Warry gives 91,000 in his book published in 1998. Hassan Pirnia in his "Iran Bastan" (1927) supported a smaller number closer to Curtius (Pirnia gave 35,000 to 40,000 men at Granikos for example, comparable to ancient sources on that battle). Alireza Shapur Shahbazi only mentioned a supposed 34,000 cavalry in his 1970's work. In 1893 Hans Delbruck infamously suggested only 40,000 to 50,000 for the Persian army at Gaugamela, which was deemed reductionist for many decades.

I would say that Darius' army at Arbela was quite large. But what I consider large for the time period and for the Achaemenids is the realm of about 60,000 men (my limit would be about 50,000 at the least and 65,000 at most). An amount of 25,000 cavalry in the Achaemenid period is an exceedingly large force, while still being in the realm of possibility for mobilization and deployment when on campaign. By comparison at the start of the industrial era (during the Napoleonic Wars) an army might field a total force of 30,000 to 50,000 cavalry. But even those large numbers are only a total at full strength, which would be extremely large and difficult to assemble on a single battlefield. In addition these forces marched and maneuvered as separate columns. In an actual battle during that era, a force might have 10,000 to 20,000 cavalry on hand.

As cavalry was a salient feature of the Persian army at Gaugamela it makes sense to focus on this portion. Regardless of the numbers given by historians it is clear that the Persians had a numerical advantage in cavalry. The historians note the presence of cavalry troops from Bactria for instance. However the cavalry contingents are relevant because they draw attention to the realities of fielding and supplying such a large force. Even more modern estimates of 40,000 cavalry are extreme and I put the maximum number at around 25,000, but 15,000 to 20,000 is preferable and perhaps more realistic. Supplying and maneuvering 25,000 cavalry would be a challenge but 40,000 simply impossible. In comparison to Alexander's forces even 15,000 cavalry would be large and any number above 20,000 especially so (as Alexander fielded maybe 8,000). The logistical difficulties of 20,000 cavalry is therefore evident and this would have to include the infantry contingents as well. Generally we would say that the amount of cavalry would not surpass 1/3 of the army and in the previous centuries it might have only amounted to 1/5 or 1/6 of the Persian army. Although many assume that the Persians had much larger cavalry forces due to the perceived equine culture of the Iranians and the nature of the Iranian plateau. Though this is not necessarily the case and I will analyze the dependency on the horse of these Iranian peoples which are mentioned in the sources.

Persian society was comparable to feudalism. As such the Persians very rarely if at all recruited their armies from the peasantry, who tended flocks and farmed. The manpower that matters is professional manpower because in the ancient times industrial level mass mobilization was pretty much impossible. As such focusing on total population or a Persian Imperial system is redundant. Most of the Persian armies were raised from among the Iranic tribes to the east. Many of the sedentary populations such as in Babylon, Egypt or the Levant did not provide a large amount of soldiers for the Imperial army. Typically they were what could be termed specialists or local provincial levies. Therefore to assume that the Achaemenid armies functioned as an Imperial system, like that of Rome or a modern system of universal conscription employed by a centralized administration, is both anachronistic and incorrect.

The Medes were the second group in the hierarchy beneath the Persian ruling elite and provided many military officers and state officials. Aside from that the Median nobility was also very powerful and largely were in control in Media itself, as lords under the Shahanshah's authority. They were less developed than the men of Pars, mostly living a semi-nomadic lifestyle in tents. While they still built some settlements and powerful citadels in the mountains. Naturally they were warlike and provided much of the cavalry to the King's army. They lived in the area of Zanjan, Qazvin, Hamadan and Markazi and then gradually pushed into Kurdistan, Kermanshah and Lurestan. This more or less corresponded to the Sassanian satrapies of Mad, Goyman and Aburdabagan. I would assume that their total amount of cavalry might number in the 5,000 to 10,000 range. Though of course we need to differentiate between manpower and mobilization.

The Hyrcanians are also referred to as Barkanians in the sources. They lived roughly in the area of Golestan and Mazandaran, which the Persians called Gurgan. Designating them as frontier peoples would actually be correct. Regardless of whether they were Iranic or not they sat firmly along the Caspian and therefore along the frontier. The number of cavalry which they could provide would likely number a couple thousand. Historically they did provide cavalry to the Shahanshah however it was their contribution of infantry in the Sassanian period (when they were called Daylamites) which were most valued. They operated within the state system as a tribe which was subject to Persian authority, as many others did as well, rather than as provincial subjects.

The Parthians were also one of these frontier peoples. Although of Iranic stock and Iranic speaking the sources relate to us that the Persians resented them for what they saw as being culturally backwards. The Parthians in the ancient times inhabited the area of Khorasan and parts of modern Turkmenistan. In the times of the Sassanians they inhabited the province of Abarshahr. More nomadic than their neighbors they seem to have settled in parts of the Sassanian provinces known as Marv and Dihistan. While the Parthians were administered by an Achaemenid satrap they are not mentioned with importance until 247 BC to 238 BC when the rebellious satrap Andragoras was killed by a "Parni" invasion from Dihistan. The Parni invasion and the establishment of the Arsacid Dynasty by the Parni king (who is called a Dahae or Bactrian) does suggest that the Parthians or perhaps their "Parni" relatives had more in common with the frontier tribes than the tribes that inhabited the Iranian plateau. At Arbela the Parthians are mentioned as being commanded by Phrataphernes. Determining their contribution would be difficult because on the one hand they were semi-nomadic so they might maintain a slightly larger amount of cavalry but on the other hand their area was probably not densely populated. Seeing as they were not one of the most powerful tribes I would put their manpower as smaller than the Medes (especially in the Achaemenid period).

The Susanians are one of the more difficult to discern. Susa corresponds to modern Khozestan province, which in those days might have had an Elamite population as well as Persians which had settled there since the 7th century BC. Neither the Elamites nor the Persians were known for their cavalry in those days, as the area of Pars and Khozestan is very mountainous. The ancient sources actually emphasize the Medes as the master riders of the ancient world, not the Persians. The Medes regarded the Persians as peasants who sometimes engaged in agriculture and were not dependent on horses. The Elamites were a sedentary peoples and this influenced the Persians to adopt cuneiform, agriculture, irrigation canals, gardening and to some extent the construction of settlements. Although the Persians were semi-nomadic and largely lived in tents, but were not necessarily traveling on horses. Many Persians still traveled on foot and it was only the very powerful elements of the nobility which had access to horses and chariots. Khuzistan, as the Sassanians called it, has plains on the other side of the mountains towards Mesopotamia. The cavalry mentioned are most likely the Persians which settled around those plains near Susa. Their horses may have been more numerous than that of the other tribes but they would not have matched the contributions in cavalry of the Medes and Bactrians, who were the main horse people of the Achaemenid Empire.

Now the Bactrians and Sogdians were Iranic speaking tribes which inhabited the frontiers of Central Asia. They quite likely had the most horses and were capable of fielding the most cavalry. As they were quite warlike they would not have a huge issue with providing soldiers for the state. It was largely these Sogdian and Bactrian tribes which were the backbone of the defense of the frontier and frequently engaged in conflicts with the Massagetae and the peoples of the Steppe. The Sogdians and Bactrians were also semi-nomadic but had settlements and large fortresses. I estimate that they could provide Darius III with some 8,000 to 10,000 cavalry and a difficult to discern amount of infantry, if any, for the Gaugamela campaign. It is not at all absurd to think that they had a total force of 20,000 to 30,000 men. However the fact that Bessos was able to orchestrate a revolt and then that the Sogdians were capable of resistance does suggest that Bessos did not bring a full force to Arbela. Not only for that reason but because Darius III would not have emptied the frontier of troops used in its defense. He would have no need for an immense force which he could not maneuver nor supply. As it is attested to in the sources the Bactrians and Sogdians only made up a portion of troops on the flanks.

I provided a maximum number of 65,000 for Darius III's field army during the Gaugamela campaign. This is not comparable to population size, a somewhat irrelevant number in the pre-industrial time periods. For the most part the exceptions are the tribal people which might be able to arm their adult population, especially nomadic peoples. Nor is it the same as the total available military forces which if we include provincial garrisons, total possible conscripts, the provincial army at Granikos, the Imperial army at Issos, Greek mercenaries and total frontier forces, in addition to the Imperial army at Gaugamela, might easily surpass 100,000 troops. But as an actual force in the field even the large army at Gaugamela could not have numbered 100,000 due to it being a logistical impossibility. Even if we accepted 65,000 as the size of the Persian army in the field we would also be required to take into account the logistics of camp followers and attendants. That in itself would probably amount to around 100,000 people which would need to be fed and organized. Now imagine how large that total would be if the Persians actually fielded say 80,000, 90,000, 100,000 or 120,000 troops.
Though it was not intentional on my part I realized that the number of about 65,000 which I concluded for the Achaemenid forces is also comparable to the Parthian and Sassanian armies. This is probably because these armies were always primarily comprised of soldiers from the Iranian plateau. While the Achaemenids also had considerable manpower in Anatolia, Darius III did not have access to these areas by 331. The logistical considerations would still be very similar as well.

[conon394]

The manpower that matters is professional manpower because in the ancient times industrial level mass mobilization was pretty much impossible

In General true, and a good post . But its worth recalling the Great King and other Persian Aristocracy were sort of a constant accumulator of wealth and related goods and horses in kind. If the King though this was the final roll of the dice he did have the ability to spend to pop what Persia could sustainably deploy even at the cost of using horses that should not have been used or green riders (compare both Germany and Japan raided their pilot pipeline for both untested pilots and the experienced trainers in WW2 when pressed). I am not defending fantastic numbers but the 'realistic' argument I think downplays what money and resources could have done for a final effort if it was manged carefully and seen as a one time affair. Why not leave the boarder undefended? If Darius lost it not it would be his problem and Alexander was demonstrably more of threat than the nomads.

[Ἀπολλόδοτος Α΄ ὁ Σωτήρ]

One should also note the logistical effort needed to deploy few hundred or a million men on the battlefield. The ancient authors seem not have been thinking about this problem when giving the numbers. Roman Army at it's peak had 450 thousand soldiers yet they were rarely able deploy numbers greater than 50 thousand for a single battle.

Why not leave the boarder undefended? If Darius lost it not it would be his problem and Alexander was demonstrably more of threat than the nomads.

The Achaemenids, just like any other state at that time, weren't capable of waging a total war, definitely not capable of utilizing all of their resources, especially manpower. They couldn't possibly recruit all of their available manpower to fight their enemies. Despite being a theoretically absolute monarch, Darius still had to contend with both Achaemenid Satraps as well as various sub-satrapal vassal city-states and tribal leaders who probably weren't too keen to send out every able-bodied man to fight Alexander.

More importantly, there's no way that people in the East were going to abandon their lands and families to be pillaged by nomads whom they'd perceive as much greater threat than Alexander. Darius could have commanded it, but he couldn't have reasonable expectations of that happening and his reputation would suffer if he'd manged to defeat Alexander by sacrificing most important Zoroastrian lands such as Bactria.

[Condottiere 40K]

At this scale, it comes down to logistics, ad the Persians had a rather effective bureaucracy and tax collection system in place, plus as it was the last roll of the dice for Darius, he probably pulled all stops.

Alexander may have surprised Darius as to his exact route of march, but Darius not only had the luxury of picking the battlefield that allowed maximum advantage to Persian tactics, but had the time to prepare it; that sort of implies that whatever forces he levied, he could supply them and their entourages, besides being on his home turf.

While a million strains credulity, a hundred thousand would not, though if Alexander's force numbered fifty thousand, and my throne was on the line, three to one with trained troops would be the minimum, and with levies, perhaps five to one.

It's quite possible that numbers counted against the Persians, as Darius starts losing control of his army, and decides discretion is the better part of valour.

[conon394]

One should also note the logistical effort needed to deploy few hundred or a million men on the battlefield. The ancient authors seem not have been thinking about this problem when giving the numbers. Roman Army at it's peak had 450 thousand soldiers yet they were rarely able deploy numbers greater than 50 thousand for a single battle.

Again I not arguing the fantastic numbers. Just the range of possibly should not be constrained by the minimal normal possibility give the dire state Darius faced and the resources he had.

The Achaemenids, just like any other state at that time, weren't capable of waging a total war, definitely not capable of utilizing all of their resources, especially manpower.

So some guy did not talk more or less all the Athenians into making themselves impoverished refugees at the mercy of Sparta (a state not exactly in love with them) and throwing the dice on winning a risk navy fight where they were outnumbered? That seems a tad total.

Despite being a theoretically absolute monarch, Darius still had to contend with both Achaemenid Satraps as well as various sub-satrapal vassal city-states and tribal leaders who probably weren't too keen to send out every able-bodied man to fight Alexander.

Maybe true maybe not really depends on which boss they thought would be better and how bad the pillaging would be. But Darius did have the cash on had to fill palms and belay worry for the moment over the prospect of gain.

More importantly, there's no way that people in the East were going to abandon their lands and families to be pillaged by nomads whom they'd perceive as much greater threat than Alexander. Darius could have commanded it, but he couldn't have reasonable expectations of that happening and his reputation would suffer if he'd manged to defeat Alexander by sacrificing most important Zoroastrian lands such as Bactria.

Was their some other invasion on tap I missed? The think is Alexander was the near and clear present danger and he had yet to show his supposed cultural clemency. He started the war based on a nominal revenge crusade.

[Lord Oda Nobunaga]

In General true, and a good post . But its worth recalling the Great King and other Persian Aristocracy were sort of a constant accumulator of wealth and related goods and horses in kind. If the King though this was the final roll of the dice he did have the ability to spend to pop what Persia could sustainably deploy even at the cost of using horses that should not have been used or green riders (compare both Germany and Japan raided their pilot pipeline for both untested pilots and the experienced trainers in WW2 when pressed). I am not defending fantastic numbers but the 'realistic' argument I think downplays what money and resources could have done for a final effort if it was manged carefully and seen as a one time affair. Why not leave the boarder undefended? If Darius lost it not it would be his problem and Alexander was demonstrably more of threat than the nomads.

Well the sources might allude to this anyway. It mentions that Darius III had a reformed infantry with longer spears. One source in particular calls them youths. If we believe the Babylonian tablets then after the defeat then Darius III's army deserted en masse. Maybe the troops which resisted at the Persian Gates were part of the army he brought to Arbela but probably also locals who joined in a last attempt to defend Iran.

The thing is though 60,000 men would be considered extremely large. It's difficult to justify more than 25,000 cavalry for both reasons of logistics and the events during the battle. Delbruck suggested that the Persians only had 12,000 cavalry because of the difficulties in supplying this many horses, the difficulty in deploying and maneuvering cavalry formations this large and because it really is hard to explain how Alexander won so resoundingly if the Persians had even 20,000 cavalry much less 40,000. Which we should just be honest 40,000 cavalry is impossible for all those reasons. Maybe some think that Welman is being milktoast or inadequate but to me that is just a nonsense number. But if Darius III had 25,000 cavalry it really is a stretch to think that 8,000 of Alexander's cavalry could have matched them regardless of any combined arms approach or whatever.

Again I not arguing the fantastic numbers. Just the range of possibly should not be constrained by the minimal normal possibility give the dire state Darius faced and the resources he had.

So some guy did not talk more or less all the Athenians into making themselves impoverished refugees at the mercy of Sparta (a state not exactly in love with them) and throwing the dice on winning a risk navy fight where they were outnumbered? That seems a tad total.

Maybe true maybe not really depends on which boss they thought would be better and how bad the pillaging would be. But Darius did have the cash on had to fill palms and belay worry for the moment over the prospect of gain.

Was their some other invasion on tap I missed? The think is Alexander was the near and clear present danger and he had yet to show his supposed cultural clemency. He started the war based on a nominal revenge crusade.

As for the amount of troops from Sogdia and Bactria well that much is easy. Even after the defeat Bessos had enough troops to put up some resistance. The Sogdian revolt was also a problem and they did some damage. There was also only small attempts by the Saka tribes to raid the frontier. Evidently Darius III didn't empty out the frontier and get all of those troops killed at Gaugamela... In spite of how severely Alexander mauled Bessos' formation. It is interesting to note that Arrian only mentions 1,000 Bactrian cavalry. He could be referring to just one formation, maybe the rest of the Bactrians were infantry. Personally I support a number of about 9,000 or 10,000. But whatever the case Arrian's number is quite telling.

The other thing to consider is that many satraps and officials in Anatolia, Ebir-Nari and Egypt had already joined Alexander. When Darius III's camp was captured after Issos that also included some of the royal family which Alexander chose to spare. Alexander's reputation was already established.

[Ἀπολλόδοτος Α΄ ὁ Σωτήρ]

So some guy did not talk more or less all the Athenians into making themselves impoverished refugees at the mercy of Sparta (a state not exactly in love with them) and throwing the dice on winning a risk navy fight where they were outnumbered? That seems a tad total.

Without modern mobilization techniques, communication lanes and road networks, I'd find a relatively homogeneous city-state, alongside its nearby countryside population, to be more reactive and able to fully utilize its resources, as opposed to a far-flung heterogeneous empire which would need to assemble its distant subjects in another part of their empire and empire materialize them on the opposite part.

Was their some other invasion on tap I missed?

While I'm not aware of any powerful nomadic confederations poised to assault the Achaemenids in the East and capable of capturing cities such as Baktra, we do know of various nomadic tribes launching raids in the Upper Satrapies, and perfectly capable looting villages and small towns. In addition to those external threats, up until 19th Century, hill-dwelling tribes would sometimes descend to the valleys to loot and pillage across many parts of Afro-Eurasia, and the Achamenid Empire was full of such tribes.

For instance I suggest reading about one such tribe, the Uxians, whom Alexander fought, not on the behalf of the Achaemenids, but because they tried to extort Alexander in a similar manner they did the Persians, despite living deep in nominal Achaemenid territory.

Maybe true maybe not really depends on which boss they thought would be better and how bad the pillaging would be. But Darius did have the cash on had to fill palms and belay worry for the moment over the prospect of gain.

Most of the Achaemenid subjects were neither Iranian nor Zoroastrian and those who were and were in high positions weren't all selfless and loyal people, Mazaeus, a Persian, simply allowed Alexander to take heavily fortified city of Babylon, while Bessus did what he did. Various tribal kings living in difficultly accessible areas weren't impressed enough with Achaemenid power to even pay them taxes, sometimes they preferred to actually tax them. And by taxing I mean robbing.

The think is Alexander was the near and clear present danger and he had yet to show his supposed cultural clemency. He started the war based on a nominal revenge crusade.

Speaking of Darius' regard or understanding of Alexander's true intentions, I think it would be good to mention that he didn't lend much support to his Satraps in Anatolia, and in relation to that how numbers Alexander faced began to increase after he'd already conquer most of Anatolia.

Again I not arguing the fantastic numbers. Just the range of possibly should not be constrained by the minimal normal possibility give the dire state Darius faced and the resources he had.

Mustering a Million men, if its true, is a quite an achievement, one that even the great Roman Empire didn't manage.

Which is why it's interesting to compare the numbers, as well as few other factors, between the Roman and Achaemenid Empires.

- Roman Army at its peak had 450K troops, according to Cassius Dio in the Battle of Lugdunum in 197, 300K were deployed, modern estimates range from 110K to 150K. This battle was a part of a civil war between Severus and Albinus and thus all the troops were Roman.

-Size of Achaemenid Army at its peak is unknown, however according to Herodotus they were capable deploying up to 2.65M during the Second Invasion of Greece, modern estimates range from 200K to 500K. we don't know if Persian had mobilized all of their available troops for this endeavor, however I personally suspect they haven't left their satrapies under-garrisoned and in my opinion they would have to do so in order to muster such massive numbers. In addition to that it took them several years to bring troops to Sardis and from there continue towards Greece.

After glorious days of Darius I and Xerxes I, the Achaemenid troops seems to have dwindled to "mere" 1M according to ancient sources, still better than the pathetic Romans with "puny" 450K and this is a relatively certain number.

When discussing the plausibility of numbers, one needs to talk of population.

The Roman Empire usually had 50-60 Million people, under Trajan around 70M Million, Achaemenid Empire 17-35 Million people. From this every 4th is an adult male. I can't stress enough that I'm being quite generous here because until the 19th Century couples usually had more than two children.

Romans had 450K troops out of, 50M, I'll use the lower estimate here which brings us to 12.5M adult males, that means that nearly every 28th adult male was a soldier, if we take that the Achaemenids had 1M troops out of, I'll use the highest population estimate of 35M which brings us to 8.75M adult males, that means that nearly every 9th adult male was a soldier.

Even when skewing the numbers in favor of the Achaemenids, by several factors, such as population number and breakdown, deployment - 1M were at a single battle, while Roman 450K never were, which would mean that the Achaemenids would need to extract an even greater number than 1M because, as I've said previously, someone needs to man the garrisons, such ability to mobilize every 9th male not withstanding serious economic and political consequences, would require a tremendous logistical and organizational effort and their deployment would be severely hampered by the state of Achaemenid geographic constraints.

Now onto actual battles.

Until Granicus in 334 it appears that Darius didn't consider Alexander as a massive threat that would require the maximum mobilization of his troops which can be seen from the fact that Alexander's numbers at Granicus were merely matched, a single year later 600K troops are at Issus and 2 years after 400K more. In short, by ancient sources at Granicus Alexander faces 40K, at Issus 600K, at Gaugamela 1M, by modern estimates it's Granicus 40K, Issus 108K, Gaugamela 120K.

Maybe modern estimates are two low and losing battles when having 2.7:1 and 2.5:1 advantage against a not just superior, but brilliant tactician, isn't that much of failure when you're a decent commander, however losing when having 15:1 and 21:1 advantage is beyond spectacular failure, even if one's an inferior commander. If we halve the numbers and get 7.5:1 and 10.6:1 advantage the failure is still spectacular.

Why did Darius even fight at Gaugamela when seeing how bad he was at Issus, when defeated at Gaugamela why did he even flee eastwards, at that time the Iranian Plateau was still far less populated and poorer than Mesopotamia and he lost a 1M troops, it's highly unlikely he'd be able to find another 1M, and let's face it how bad he is he'd need at least 2M, to get that decent 42:1 advantage.

It all boils down to whether or not Alexander's victories were impressive enough unless he was outnumbered at least 4:1, personally I'd say yes. If the numbers are true, Darius was either mentally impaired, or it was true what so many ancients believed, Alexander was divine. Lastly, ther's something special about the Achaemenids because no other state deployed such numbers on the battlefield apart from the Chinese during the Warring States, if we are to believe their ancient sources, and If I'm not mistaken, even they didn't have a 1M on the battlefield.

[Dick Cheney.]

My two cents.

Generally the Achaemenid army is considered to have been an absolutely massive force comprised of all the peoples and tribes of the Persian Empire. Ancient writers ascribed to the Persians incredible numbers. For the Battle of Gaugamela Arrian claimed 1 million infantry…

Okay, nobody doubts that 1,000,000 men is an exaggeration, but everyone agrees (from Herodotus to Arrian to modern historians) that the Persians fielded the largest armies of anybody in the ancient world. There’s not one writer -or primary source that I am aware of- that disputes that. In every set piece battle with the Greeks, the Persians always outnumbered their foe.

In addition, Gaugamela was years in the making, coming at least 2 years after Issus. And on top of that everyone knew from Alexander to Darius’s royal court that the next battle would be decisive – and the political calculus for both leaders was decisive battle. Both leaders desperately hungered for legitimacy, and Darius -after losing a portion of his empire- could not afford to be beaten again.

We should expect then -given the stakes and close proximity to the Persian heartland- that the numbers on the Persian side would be exceptionally large.

In short, a “massive force” on the Persian end is not an exaggeration. And Gaugamela, no matter what anyone says (modern estimates be damned) was going to be an outlier.

I would say that Darius' army at Arbela was quite large. But what I consider large for the time period and for the Achaemenids is the realm of about 60,000 men (my limit would be about 50,000 at the least and 65,000 at most). An amount of 25,000 cavalry in the Achaemenid period is an exceedingly large force, while still being in the realm of possibility for mobilization and deployment when on campaign. By comparison at the start of the industrial era (during the Napoleonic Wars) an army might field a total force of 30,000 to 50,000 cavalry. But even those large numbers are only a total at full strength, which would be extremely large and difficult to assemble on a single battlefield. In addition these forces marched and maneuvered as separate columns. In an actual battle during that era, a force might have 10,000 to 20,000 cavalry on hand.

Darius had enough men to envelop Alexander, and the desert plains of Gaugamela were specifically chosen for that purpose. Any estimate of Darius force then should start there.

I’m not going to give you a number but given that Alexander’s estimates are usually around 47,000 (and the numbers for the Macedonian Army seem to be fairly accurate) I’m not going to discount a 2-1 advantage on the Persian side; so 90,000 is possible for me.

If we’re going to believe what we think happened; that Parmenio got enveloped and that Alexander had to preplan a second battle line, and that the Persians still managed to sack the Macedonian camp by super stretching the Macedonian lines, then we must believe then that the Persians badly outnumbered Alexander.

As cavalry was a salient feature of the Persian army at Gaugamela it makes sense to focus on this portion. Regardless of the numbers given by historians it is clear that the Persians had a numerical advantage in cavalry. The historians note the presence of cavalry troops from Bactria for instance. However the cavalry contingents are relevant because they draw attention to the realities of fielding and supplying such a large force. Even more modern estimates of 40,000 cavalry are extreme and I put the maximum number at around 25,000, but 15,000 to 20,000 is preferable and perhaps more realistic. Supplying and maneuvering 25,000 cavalry would be a challenge but 40,000 simply impossible.

Why not? You haven’t given us any numbers yet that would think obtaining 25,000-40,000 horses would be impossible – other than 40,000 is a big number.

As you elude to later, Cyrus the Great made cavalry a mainstay in the Persian Army and attached prestige and social standing to raising horses. Given that the population size for the Persian Empire was close to 35-50 million people (480BC estimate) and encompassed 2.9 million sq miles, I’m sure they could find and raise at least 25,000 ponies.

Persian society was comparable to feudalism. As such the Persians very rarely if at all recruited their armies from the peasantry, who tended flocks and farmed. The manpower that matters is professional manpower because in the ancient times industrial level mass mobilization was pretty much impossible. As such focusing on total population or a Persian Imperial system is redundant. Most of the Persian armies were raised from among the Iranic tribes to the east. Many of the sedentary populations such as in Babylon, Egypt or the Levant did not provide a large amount of soldiers for the Imperial army. Typically they were what could be termed specialists or local provincial levies. Therefore to assume that the Achaemenid armies functioned as an Imperial system, like that of Rome or a modern system of universal conscription employed by a centralized administration, is both anachronistic and incorrect.

Sorry Oda (and I do mean to be sincere) but this is your weakest point. Any attempt to compare Persian society to feudalism is just flat out wrong.

The Persians were an urban society -inheriting the first cities in history- complete with a network of ports, royal roads, tax centers, forts, walled cities, supply depots, and the first postal system in history. If anything I would compare it to an Imperial system, not unlike Rome.

The beauty of the Persian system of course were the Satrapies – 25 to 35 different provinces give or take, which replaced the vassal system of client kings.

Each of these provinces had a governor, general, and a regular garrison. More importantly however, the Satrapies proved to be a reliable source for tax collection – so reliable in fact the Persians came out with the first national budgets.

Given also Darius I’s remarkable coinage system -based on gold and silver and supplied by mines in India and Asia Minor-, use of inspectors, a standing army, and the remarkable centralization of government authority -through a professional class of soldiers and administrators- and I don’t see how any other label could apply to the Persian Empire but a kingdom with a sovereign ruler.

I provided a maximum number of 65,000 for Darius III's field army during the Gaugamela campaign. This is not comparable to population size, a somewhat irrelevant number in the pre-industrial time periods. Nor is it the same as the total available military forces which if we include provincial garrisons, total possible conscripts, the provincial army at Granikos, the Imperial army at Issos, Greek mercenaries and total frontier forces, in addition to the Imperial army at Gaugamela, might easily surpass 100,000 troops. But as an actual force in the field even the large army at Gaugamela could not have numbered 100,000 due to it being a logistical impossibility. Even if we accepted 65,000 as the size of the Persian army in the field we would also be required to take into account the logistics of camp followers and attendants. That in itself would probably amount to around 100,000 people which would need to be fed and organized. Now imagine how large that total would be if the Persians actually fielded say 80,000, 90,000, 100,000 or 120,000 troops.

That facts are Persian logistics were second to none (even greater than Alexander in my view) and included feats like this:



and engineering like this:

Herodotus on Cyrus Capture of Babylon: Cyrus was now reduced to great perplexity, as time went on and he made no progress against the place. In this distress either some one made the suggestion to him, or he bethought himself of a plan, which he proceeded to put in execution. He placed a portion of his army at the point where the river enters the city, and another body at the back of the place where it issues forth, with orders to march into the town by the bed of the stream, as soon as the water became shallow enough: he then himself drew off with the unwarlike portion of his host, and made for the place where Nitocris^note dug the basin for the river, where he did exactly what she had done formerly: he turned the Euphrates by a canal into the basin, which was then a marsh, on which the river sank to such an extent that the natural bed of the stream became fordable. https://www.livius.org/sources/conte...takes-babylon/[​{

I see no reason to believe then, given an actual navy, military roads, professional administrators, a professional class of soldiers, walled cities and currency, a postal system, a rudimentary budget, and an unbelievably talented engineer corps -along with the vast material wealth of the empire- that the Persians did not have the best logistics and finest power projection capabilities of anyone in the entire world.

Though it was not intentional on my part I realized that the number of about 65,000 which I concluded for the Achaemenid forces is also comparable to the Parthian and Sassanian armies. This is probably because these armies were always primarily comprised of soldiers from the Iranian plateau. While the Achaemenids also had considerable manpower in Anatolia Darius III did not have access to these areas by 331. The logistical considerations would still be very similar as well.

Yet we still haven’t even considered yet the reverse could also be true. Persian gold was the envy of the entire world; which funded self-sufficient mercenaries and allowed them to buy supplies from anyone (why even pillage or waste resources feeding and training your own troops?). We also know that supplying armies could be big business to local economies (Alexander’s army was considered a mobile city), why let it be a drag? Also because Persian infantry was generally lighter & mobile – meant they could carry more or operate with less. And it was Ox carts (not horses)-carrying 1,450 lbs according to Xenophon- that kept the armies fed.

Finally, you also inexplicably discounted total population. With a pop count of 35 million, why wouldn’t there be enough people left to gather crops or feed the horses??

TLDR
Huge Persian armies are more plausible then we think.

[Lord Oda Nobunaga]

Okay, nobody doubts that 1,000,000 men is an exaggeration, but everyone agrees (from Herodotus to Arrian to modern historians) that the Persians fielded the largest armies of anybody in the ancient world. There’s not one writer -or primary source that I am aware of- that disputes that. In every set piece battle with the Greeks, the Persians always outnumbered their foe.

I'm really just making note of the figures given throughout the years. So yes the ancient sources are clearly wrong, even Curtius Rufus 245,000 is impossible. But also I am saying that modern estimates of 90,000, 100,000 or 120,000 can't be correct either.

In addition, Gaugamela was years in the making, coming at least 2 years after Issus. And on top of that everyone knew from Alexander to Darius’s royal court that the next battle would be decisive – and the political calculus for both leaders was decisive battle. Both leaders desperately hungered for legitimacy, and Darius -after losing a portion of his empire- could not afford to be beaten again.

Taking into account the losses at Issos and the loss of territory in the west, including the loss of the extremely crucial Egyptian wealth and Anatolian recruits... Darius III would have been entirely raising his army from the eastern half of the empire. Knowing this fact the Persians at Issos would logically have more resources to raise a larger army and yet it is at Gaugamela when the Persians have the larger army. Unless ancient Iran had clone trooper factories or massive settlements then you can't ascribe to them the numbers which you are claiming. In the latter case massive settlements does not necessarily amount to lots of troops. Many urban populations would have been useless as this history shows anyway, which is why the Persians recruited most of their troops from the east, some local provincial levies, specialists like people from Egypt for instance and the warlike peoples of Anatolia and occasionally some Greek mercenaries.

Not really, Alexander's fear was that Darius III wouldn't give battle. Ultimately both leaders were gambling on a pitched battle but that says nothing about the size of either army. If Alexander was really so completely outnumbered then his decision would have been madness, not genius.

We should expect then -given the stakes and close proximity to the Persian heartland- that the numbers on the Persian side would be exceptionally large.

No we shouldn't. Arbela is all the way in northern Mesopotamia along the Tigris. Darius had to collect and march his army from the Iranian plateau and all the way in the east, march down through Khuzistan or Kermanshah directly to Babylon and then march north to Arbela. It probably makes more sense to assume that Darius III assembled his army in Babylon in order to march the other troops through the Iranian plateau as various columns. Then Darius III marched his army north from Babylon, towards Arbela and then had to deploy his whole army near the hill of Gaugamela where they camped for some time waiting for Alexander to arrive. However long they spent marching along the way and then however long they spent in Babylon should be taken into account as well. "Proximity" isn't really a factor anyway and in this case the proximity argument isn't even true either.

In short, a “massive force” on the Persian end is not an exaggeration. And Gaugamela, no matter what anyone says (modern estimates be damned) was going to be an outlier.
.......
TLDR
Huge Persian armies are more plausible then we think.

And I am saying all of this, but that doesn't tell us what it actually means.
Problem with this is that I am not arguing whether Darius III had a very large army. Instead I am questioning what really constitutes a large army. In those days 60,000 is absolutely massive.

Darius had enough men to envelop Alexander, and the desert plains of Gaugamela were specifically chosen for that purpose. Any estimate of Darius force then should start there.

uuuuhh... Hannibal enveloped the largest Roman army ever put to the field with less than 60,000 men.
Evidently you don't need a 2:1 or 3:1 superiority to do so. Darius III just had to outflank Alexander's formations and route their wings. His center was firmly defended by a hill. By contrast Alexander only had like 8,000 cavalry. Some 15,000 cavalry is enough to match it much less 20,000 or 25,000.

I’m not going to give you a number but given that Alexander’s estimates are usually around 47,000 (and the numbers for the Macedonian Army seem to be fairly accurate) I’m not going to discount a 2-1 advantage on the Persian side; so 90,000 is possible for me.

Some 47,000 is already a massive army. Not just for Alexander and the Greeks but in general.
Is there really any reason to assume that the Persians had a 2:1 advantage?
60,000 or so to 47,000 is already pretty good odds for the Persians. The fact that Alexander won therefore really has nothing to do with raw numbers.

If we’re going to believe what we think happened; that Parmenio got enveloped and that Alexander had to preplan a second battle line, and that the Persians still managed to sack the Macedonian camp by super stretching the Macedonian lines, then we must believe then that the Persians badly outnumbered Alexander.

There are so many interpretations which we could make that this is barely useful.

Why not? You haven’t given us any numbers yet that would think obtaining 25,000-40,000 horses would be impossible – other than 40,000 is a big number.

As you elude to later, Cyrus the Great made cavalry a mainstay in the Persian Army and attached prestige and social standing to raising horses. Given that the population size for the Persian Empire was close to 35-50 million people (480BC estimate) and encompassed 2.9 million sq miles, I’m sure they could find and raise at least 25,000 ponies.

This is the main problem with your thinking.
1. It makes no sense to account for the total population of the Persian Empire. The people used for military campaigns were mostly people from the east. Mostly Iranic peoples in the Iranian Plateau and people from Central Asia. The other major area for recruitment was Anatolia.

2. Horses were largely bred in Central Asia and the Iranian Plateau because those were the nomadic people who raised herds and who rode them into battle. Areas of Anatolia known for its horses, particularly Cappadocia and Phrygia.

3. The total population is irrelevant, especially those urban populations which are useless for campaigning. If there is anything to be learned about Middle Eastern history (and in general) it is that urbanized peoples are fairly useless for campaigning. In so far as the actual warfare is concerned it was waged by professionals who could campaign and do battle while still being reasonably supplied. Having hundreds of thousands of conscripts which are useless in combat and can't be supplied is actually counter productive. Self defeating in a war of annihilation or war of attrition.

4. Territory is irrelevant. The only areas conducive to horse breeding would have been Central Asia, the area of Media and the Caspian, roughly the plains of Susa since Fars is actually mountainous, the plains in the east around Khorasan and the plains of Anatolia and Armenia.

5. Most of this doesn't matter anyway because by the time of Gaugamela, Darius III only had the areas in the east. So his horses, supplies, recruits would have all been from the east. Darius could very well have 25,000 or 40,000 mounted troops but the question is can he march all of these troops over the mountains, to Babylon and then up the desert terrain towards Arbela and keep them in good shape and supplied. We're only looking at a portion of the empire by this point.

6. It isn't a question of totals, it is a question of how many can be assembled, supplied and deployed. Specifically Darius III was required to assemble his forces in Babylon, supply them with Babylonian grain and march them overland as one column to Arbela. Assuming he had mobilized 100,000 men he wouldn't have been able to move all of those troops as part of a single column and then deployed all of them at Gaugamela. Hence a manageable force of 50,000 or 60,000 makes more sense.

Sorry Oda (and I do mean to be sincere) but this is your weakest point. Any attempt to compare Persian society to feudalism is just flat out wrong.

The society of the Persians, that is to say the Iranic people was similar to Feudalism. We could call it something else but so long as the point gets across that society was divided and a class of people functioned as essentially a warrior class.

The Persians were an urban society -inheriting the first cities in history- complete with a network of ports, royal roads, tax centers, forts, walled cities, supply depots, and the first postal system in history. If anything I would compare it to an Imperial system, not unlike Rome.

The Persians were most definitely not urbanized. The Persian people were semi-nomadic and lived in the mountains and plains of the Iranian plateau. Most of the Iranians lived in tents and only had very few settlements, not at all comparable to massive cities like Babylon, Damascus etc.

The Achaemenid Empire was not at all comparable to Rome. Maybe only in so far as the Satrap administration is somewhat similar to the Roman provincial system but even that is a stretch. Considering that the Romans originated as a Polis which expanded into an Imperial realm of sorts built a bunch of Colonias as cities and could conscript citizens and Socii on an almost universal level. Where as the Persians started out as a series of tribes in roughly the area of Pars and Elam and created a system of affiliated kingdoms and crowns but their society being organized on a feudal basis and not on a modern or Roman Imperial basis, regardless of the reorganization into satrapies in the reign of Darius I. This is the anachronism and factual error which is often repeated and is frankly annoying and not at all conducive to understanding Persian history.

What you are referring to is actually the other peoples of the Achaemenid Empire such as the Babylonians, Arameans, Egyptians etc. Most of these urban peoples were not recruited as soldiers, Achaemenid armies were largely composed of the Iranic tribes. The actual soldiers were drawn up from the warriors in the society not the peasantry. This is why I am inherently pointing out that it isn't just about population but also social structure, culture and urbanization as well. The fact that most of the Iranian people did not live in cities was an advantage for them when it came to warfare. The fact that only a segment of their society could provide mounted warriors goes towards a level of professionalism.

The beauty of the Persian system of course were the Satrapies – 25 to 35 different provinces give or take, which replaced the vassal system of client kings.

Most of which don't matter because Darius III had lost them by the time of Gaugamela.
Satrapies are really only useful in raising local levies for defensive purposes in this case. The large campaigning armies would have been Iranic.

In so far as local populations are concerned it was mostly colonists from Mesopotamia which were resettled in places like Syria and Anatolia, the native Anatolians and Greek mercenaries but also Persians, Medes and Bactrians which were resettled in these areas for military purposes. Not only did the Persians raise their armies from Iranians in the east but they evidently realized their dependence on these peoples for military matters that they resettled some of them in other satrapies.

Even the internal structure within a satrapy or region could be described as feudal. The Iranic nobility was bound to the king and they in turn controlled large amounts of land with peasants and soldiers. The society itself could also be described as a feudal caste system which separated the peasantry from the warriors, nobility and priests. This also happened to be the case in other areas such as Anatolia where most of these peoples had a similar caste which separated the warrior class.

Each of these provinces had a governor, general, and a regular garrison. More importantly however, the Satrapies proved to be a reliable source for tax collection – so reliable in fact the Persians came out with the first national budgets.

You're trying to compare administrative structure with the societal structures of these Iranic peoples. Who I would add are the ones that make up the Achaemenid armies. Which is what I was referring to when I said a feudal structure. Moreover these local peoples also had similar societal structures in particular the Anatolians who practiced a sort of Feudalism. I am not referring to a Medieval Feudalism but it doesn't matter, the general meaning is there so don't get stuck on the word.

Given also Darius I’s remarkable coinage system -based on gold and silver and supplied by mines in India and Asia Minor-, use of inspectors, a standing army, and the remarkable centralization of government authority -through a professional class of soldiers and administrators- and I don’t see how any other label could apply to the Persian Empire but a kingdom with a sovereign ruler.

The coinage was largely used to pay mercenaries. In particular Anatolians and Greeks... so completely irrelevant in this case.
The professional class of soldiers again, was overwhelmingly Iranians from the military castes. The command economy of the Persian kings doesn't matter because the issue is not one of costs or supply but in transporting tonnes of supplies from point A to B.

That facts are Persian logistics were second to none (even greater than Alexander in my view) and included feats like this:

and engineering like this:

I see no reason to believe then, given an actual navy, military roads, professional administrators, a professional class of soldiers, walled cities and currency, a postal system, a rudimentary budget, and an unbelievably talented engineer corps -along with the vast material wealth of the empire- that the Persians did not have the best logistics and finest power projection capabilities of anyone in the entire world.

Again, who says that they didn't? That doesn't mean they could field 100,000 men in a single campaign. Even historically this sort of thing was practically unheard of until around the 1700's or 1800's. Even the Romans would have struggled to field armies this large.

What is more we could use the precedent argument. When did anyone field armies this large until now? The largest Assyrian army ever put into the field was probably 40,000 or 50,000 at most and in the Bronze Age an army could not have surpassed 30,000. But all of a sudden we are making the huge leap to 90,000 or 100,000.

Yet we still haven’t even considered yet the reverse could also be true. Persian gold was the envy of the entire world; which funded self-sufficient mercenaries and allowed them to buy supplies from anyone (why even pillage or waste money feeding and training your own troops?). We also know that supplying armies could be big business to local economies (Alexander’s army was considered a merchant city), why let it be a drag? Also because Persian infantry was generally lighter & mobile – meant they could carry more or operate with less. And it was Ox carts (not horses)-carrying 1,450 lbs according to Xenophon- that kept the armies fed.

Finally, you also inexplicably discounted total population. With a pop count of 35 million, why wouldn’t there be enough people left to gather crops or feed the horses??

The only consideration we really need to take into account is moving supplies as well as being capable of organizing however many troops. This isn't limited to the soldiers themselves but also includes pack animals, war horses, attendants and camp followers. For every person that is marching you need the grain to feed them, for all the grain you need pack animals to transport it, for all the pack animals you need the grain to feed them and then the means to transport them. Even if you had infinity slaves or mules to move all this you would just be adding another mouth to feed. It is now easy to have an idea of where it peaks.

What is more having 25,000 or 40,000 cavalry increases the logistical strain. Not only would they have to provide for the riders but also their war horses, considerably more than a soldier, attendant or pack animal. Then add all the spare war horses for the riders. So if we did increase the number of cavalry to 40,000 then there is much less of a way to justify an additional 50,000 or 60,000 infantry to give us a round sum on 90,000 or 100,000 troops (plus all the attendants). Assuming we accept 40,000 cavalry the logistical strain is much greater than say 20,000 cavalry. In that case it would actually support a total closer to my suggested 60,000 (40,000 cavalry with 20,000 infantry). The issue here is that there is no chance in hell that Alexander could have defeated 40,000 cavalry with only 8,000 of his own and whatever combination of infantry support. Honestly I'm having a hard time justifying even 25,000 cavalry in so far as logistics and explaining how it was that the Persians managed to lose. It isn't until the Napoleonic Era in which a single army is capable of fielding cavalry forces in the range of 30,000 or 40,000 anyway. Which would not have marched as part of a single force but various forces which would assemble at a single point. The complete opposite of what we are discussing here.

This is the reason why I focus on cavalry. If we can determine the amount of cavalry we would have a better position to determine the total army but also logistical constraints. The Iranic peoples I mention in the first post are the ones mentioned in the sources as being present at Gaugamela. Usually someone will assume that these people had a massive amount of cavalry troops but as I went over it we see that at this point in time that is not really the case. Since these are the ones mentioned as providing cavalry then we have an even better picture. Logically smaller tribes like the Susanians and Barkanians would not have provided huge cavalry contingents.

[conon394]

1,450 lbs according to Xenophon

It interesting to see what a long life Burford's miscalculation has had after been jumped on the Lynn White and people like Engels uncritically - in terms of diminishing the capacity of wagon transport. The cost of it might not be profitable for a person in the private market but cost was certainly not a problem for the King.

[Azorica]

Damn got beat by Dick Cheney!

But to complement: Feudalism in Western Europe was a consequence of both economic demonetization and colapse of central bureaucracy and didn't exist in the Achaemenid Empire. For "legal" purposes, the Achaemenid king was the sole owner of the land, with satraps ruling locally in his behalf with the aid of central government agents that reported to the king alone. Although these administrations could sometimes be corrupt, the system was overall efficient considering the times, that's why subsequent persian-based empires such as Parthians and Sassanids kept the administration in similar molds, although the Parthian model was more decentralized. It could have had some tributary/vassal-overlord relation to some tribes that could be passed on as proto-feudalism but overall it was a highly centralized, bureaucratic empire, more in common with the Romans that with medieval Europe. Rome following the tax reforms of Augustus that stopped the practice of tax farming would also be a rather centralized affair, with magistrates and bureaucracy keeping the whole thing going, even though there were some proto-feudal relations as the imperial hierarchy allowed such autonomous states to exist (such as the Herodian Kingdom and the Kingdom of Palmyra), making it very much like the Achaemenids. The Eastern Romans were mostly centralized until the pronoiai reforms of the late 12th century turned the empire into a more feudal state as they became hereditary. The first pronoiai were meant was a way to pay someone with a land grant instead of funds but for all purposes the land was still the emperor's who could revoke it at will.

Like said before, they were a highly urbanized, with infrastructure, depots, roads, navy, so on, so the modern estimates of a 90 000-120 000 army, although strenuous in ancient times and being highly unpopular with local populations due to requisitions, even if paid (As Sun Tzu wrote: "[...]the proximity of an army causes prices to go up; and high prices cause people's substance to be drained away") is not impossible considering the previous facts and the fact is that the Persians had access to highly productive provinces such as Egypt and Mesopotamia and had the infrastructure to sustain a large army and a large tax base to pay for both troops and supplies and gold is gold. Proof of this is that Greek mercenaries fought for the persian side at Gaugemela. The concept of nationalism was still a mirage back then. Also we know that apart from local forces and garrisons, the Persians had a standing force, the Immortals, that were alive and kicking in the eve of Alexander's invasion and were present in Gaugemela. To support this idea, the Romans, with pretty much the same logistical technology fielded 10 to 12 legions in the Battle of Arausio, plus allies. It was strenuous, it wasn't common but it was possible.

The historians note the presence of cavalry troops from Bactria for instance. However the cavalry contingents are relevant because they draw attention to the realities of fielding and supplying such a large force. Even more modern estimates of 40,000 cavalry are extreme and I put the maximum number at around 25,000, but 15,000 to 20,000 is preferable and perhaps more realistic.

Xenophon in Anabasis mentions mucking around in a village that reared horses as tribute to the Great King, which the Greek... ahm... "borrowed" for their own use as the expeditionary force had a severe lack of mounted troops which limited both chasing and scouting potential (on a side note I think they left some loot as compensation so the villagers heads wouldn't roll but can't say for sure as I read it quite a while ago ). That means the Persians had a state-wide system to rear horses for cavalry purposes. One must remember that most of this cavalry was usually lightly armed and used javelins and such more often when compared to "later editions of the model" but still they had the capability and system in place to rear horses for the state, a model that the Romans also emulated with the equus publicus. In the Napoleonic period horses were more often than not, also raised for military purposes: difference being the a more intensive regime. If they fielded those numbers in Gaugemala can be debated, but an empire as large as the Achaemenids could rear those numbers and horses can be fed with grains transported by supply ox wagons which were the norm until Alexander, influenced by Xenophon, abandoned the practice to favor mobility and they can forage much farther than the common infantryman.

As such the Persians very rarely if at all recruited their armies from the peasantry, who tended flocks and farmed. The manpower that matters is professional manpower because in the ancient times industrial level mass mobilization was pretty much impossible. As such focusing on total population or a Persian Imperial system is redundant. Most of the Persian armies were raised from among the Iranic tribes to the east. Many of the sedentary populations such as in Babylon, Egypt or the Levant did not provide a large amount of soldiers for the Imperial army. Typically they were what could be termed specialists or local provincial levies. Therefore to assume that the Achaemenid armies functioned as an Imperial system, like that of Rome or a modern system of universal conscription employed by a centralized administration, is both anachronistic and incorrect.

Universal conscription is a late 18th century idea. Before that there were events of gang presses or limited conscription but not on the levée en masse style that would be the trademark of modern armies until the late 20th century.

About the eastern iranic tribes: Not quite. Although they didn't have standing army the size of the Romans, only the Immortals, which was composed of ethnic persians but open to others such as medians, as the definition of "persiness" was quite loose, and they did recruit from tribes, such as the Scythians, they also levied from the provinces. They had a system close to the Greeks and common in antiquity of citizen-militia. Take for example the Sparabara. They trained to be soldiers but when not required in campaigns, they stayed home training, hunting, farming, grazing, knitting, whatever they felt like. They functioned as frontline troops spearman but far lighter than hoplites/phalangites, which would prove their undoing (who would have guessed wicker shields lose against metal?).

Median-style bowmanship was used extensively and many of those archers were indeed of median stock. Elamites, Babylonians and so on also joined the ranks. In fact Xenophon mentions that they outranged the Cretans self-bows and harrased them constantly. The Cretan contingents of Alexander and light peltasts suffered at the hands of the Persian archers. The Persians had a great archery tradition with composite bows apart from cavalry. In both these aspects they were overall superior to their greek neighbours, with maybe the exception of the Thessalians and the Macedonians on the cavalry department and the Cretans on the archery one. They were however inefficient against heavy armored hoplites in tight formation and several accounts of Xenophon of them facing Persian light infantry usually ends up with the Persian side running, using their mobility advantage, before the hoplite onslaught with the hoplites with little to no casualties. May be an exaggeration by the author but explains why those tactics failed later against equally heavy phalangites: the arrows simply bounced on the pike cover or failed to penetrate the linothorax of the Macedonian infantry and Persian line infantry wasn't as disciplined and well armored as the macedonian/greek army that not even the scythed chariots and elephants could break.

[Lord Oda Nobunaga]

But to complement: Feudalism in Western Europe was a consequence of both economic demonetization and colapse of central bureaucracy and didn't exist in the Achaemenid Empire.

That's because my use of the term feudalism is not an exact meaning to Medieval Feudalism.
Now what I am saying is that Persian society had a similar feudal structure in which land owners controlled estates with peasants and soldiers. When the King of Kings raised his army it was from these land owners in Iran, not necessarily the satrapies. He didn't need to conscript the peasants because there was already a landed elite who served as the warrior class.

For "legal" purposes, the Achaemenid king was the sole owner of the land, with satraps ruling locally in his behalf with the aid of central government agents that reported to the king alone.

I'm not talking about satrapies though. I am referring to the Medo-Persian tribal elite. However in a lot of these places the method of recruitment was the same. The satrap or king could order coins to be struck and use these to recruit locals as mercenaries, or foreign mercenaries (particularly Greeks), or recruit troops from the local elite. Anatolia especially had powerful landed families which provided soldiers for Croesus and later Mithridates of Pontus.

Although these administrations could sometimes be corrupt, the system was overall efficient considering the times, that's why subsequent persian-based empires such as Parthians and Sassanids kept the administration in similar molds, although the Parthian model was more decentralized. It could have had some tributary/vassal-overlord relation to some tribes that could be passed on as proto-feudalism but overall it was a highly centralized, bureaucratic empire, more in common with the Romans that with medieval Europe.

Feudalism and centralization are not mutually exclusive. You are taking my use of "feudalism" to mean that the magnates and lords are being empowered in some disproportionate way. When really all I am saying is that there existed a hierarchical class structure in which nobles are given control over land and in turn fulfill obligations to their king. We have many examples of this during the Renaissance, Sengoku Japan, China and of course Persia and the later Islamic states.

The Sassanids and Parthians probably had more of a feudal like structure than the Achaemenids. In those cases there are powerful families with large territories and probably as a result a huge amount of influence within state affairs. In spite of that the King of Kings still retained a central control and that is because the granting of lands did not necessarily mean that the King was relinquishing ownership.

Like said before, they were a highly urbanized, with infrastructure, depots, roads, navy, so on, so the modern estimates of a 90 000-120 000 army, although strenuous in ancient times and being highly unpopular with local populations due to requisitions, even if paid (As Sun Tzu wrote: "[...]the proximity of an army causes prices to go up; and high prices cause people's substance to be drained away") is not impossible considering the previous facts and the fact is that the Persians had access to highly productive provinces such as Egypt and Mesopotamia and had the infrastructure to sustain a large army and a large tax base to pay for both troops and supplies and gold is gold.

CONTEXT!!!
For starters no, the PERSIAN PEOPLE were not highly urbanized. Iran at the time was not densely populated and had only a few towns, no massive cities and the population mostly lived in tents.

Second of all, Darius III would have had more resources during the time of Issos and yet he has the larger army at Gaugamela. So evidently this is not really a major factor.

Third, by the time of Gaugamela Darius III did not have control of the western satrapies and the only lucrative province under his control was Babylonia. Not to mention that Alexander had captured his camp as well as his treasury.

Proof of this is that Greek mercenaries fought for the persian side at Gaugemela. The concept of nationalism was still a mirage back then. Also we know that apart from local forces and garrisons, the Persians had a standing force, the Immortals, that were alive and kicking in the eve of Alexander's invasion and were present in Gaugemela. To support this idea, the Romans, with pretty much the same logistical technology fielded 10 to 12 legions in the Battle of Arausio, plus allies. It was strenuous, it wasn't common but it was possible.

Those Greek mercenaries were the survivors of Issos but we don't even know how much there were. Not sure what nationalism has to do with this, or what you mean by it.
Roman recruitment was completely different from the Persians. But even in that case I am skeptical that the Romans raised 10 to 12 legions to fight some barbarians when in the 2nd Punic War they raised 8 legions for Cannae and Caesar had 8 to 10 legions to subdue all of Gaul.

Xenophon in Anabasis mentions mucking around in a village that reared horses as tribute to the Great King, which the Greek... ahm... "borrowed" for their own use as the expeditionary force had a severe lack of mounted troops which limited both chasing and scouting potential (on a side note I think they left some loot as compensation so the villagers heads wouldn't roll but can't say for sure as I read it quite a while ago ). That means the Persians had a state-wide system to rear horses for cavalry purposes. One must remember that most of this cavalry was usually lightly armed and used javelins and such more often when compared to "later editions of the model" but still they had the capability and system in place to rear horses for the state, a model that the Romans also emulated with the equus publicus. In the Napoleonic period horses were more often than not, also raised for military purposes: difference being the a more intensive regime. If they fielded those numbers in Gaugemala can be debated, but an empire as large as the Achaemenids could rear those numbers and horses can be fed with grains transported by supply ox wagons which were the norm until Alexander, influenced by Xenophon, abandoned the practice to favor mobility and they can forage much farther than the common infantryman.

My point is that even in a developed state like Napoleonic France, they struggled to field more than 30,000 cavalry. They didn't even march as a single force for reasons of supply and had to march as separate columns. This was in a time of modern urbanization, much more advanced infrastructure, the beginning of modern industry, massive agricultural output, massive population growth and modern bureaucracies. How then could we justify the claim that the Persians could somehow field 40,000 cavalry as one army? What exactly would they forage in Mesopotamia? The horses wouldn't have anything to graze on and half the march is over the desert in central Mesopotamia where Sassanians and Romans struggled for a century.

About the eastern iranic tribes: Not quite. Although they didn't have standing army the size of the Romans, only the Immortals, which was composed of ethnic persians but open to others such as medians, as the definition of "persiness" was quite loose, and they did recruit from tribes, such as the Scythians, they also levied from the provinces. They had a system close to the Greeks and common in antiquity of citizen-militia. Take for example the Sparabara. They trained to be soldiers but when not required in campaigns, they stayed home training, hunting, farming, grazing, knitting, whatever they felt like. They functioned as frontline troops spearman but far lighter than hoplites/phalangites, which would prove their undoing (who would have guessed wicker shields lose against metal?).

No the Iranic peoples were divided into tribal affiliations. That in itself does not mean that they were steppe nomads like the Dahae or the Massagetae. The "feudalism" was the result of these tribal associations. For instance Cyrus' capital at Pasargadae was the tribe which he belonged to and the ruling tribe of Fars at the time. The actual society was divided into a hierarchical caste in which the nobility controlled land with peasants and soldiers. I doubt that the so called "Immortals" were actually a standing army, probably just the King's personal levy from the warriors on his direct land. The actual standing "army" must have been the couple thousand guard troops, the so called "companions" or "apple bearers".

Median-style bowmanship was used extensively and many of those archers were indeed of median stock. Elamites, Babylonians and so on also joined the ranks. In fact Xenophon mentions that they outranged the Cretans self-bows and harrased them constantly. The Cretan contingents of Alexander and light peltasts suffered at the hands of the Persian archers. The Persians had a great archery tradition with composite bows apart from cavalry. In both these aspects they were overall superior to their greek neighbours, with maybe the exception of the Thessalians and the Macedonians on the cavalry department and the Cretans on the archery one. They were however inefficient against heavy armored hoplites in tight formation and several accounts of Xenophon of them facing Persian light infantry usually ends up with the Persian side running, using their mobility advantage, before the hoplite onslaught with the hoplites with little to no casualties. May be an exaggeration by the author but explains why those tactics failed later against equally heavy phalangites: the arrows simply bounced on the pike cover or failed to penetrate the linothorax of the Macedonian infantry and Persian line infantry wasn't as disciplined and well armored as the macedonian/greek army that not even the scythed chariots and elephants could break.

Babylonians were not a massive component of the Achaemenid army. Mostly it was composed of Medes and Persians but since the Persians lacked horses much of the cavalry was recruited from the Medes and Bactrians among other Iranic peoples. In the latter half of the Achaemenid period they began to resettle Persians, Medes, Bactrians, Babylonians and Assyrians in Ebir-Nari (Syria) and across Anatolia as part of military colonies. Which clearly indicates that these Iranic tribes were crucial in the empire's military power but also that they could make use of the Mesopotamians in a similar capacity. Though Anatolia was a rather self sufficient area since it had many useful Anatolian peoples which could be recruited as well as Ionians and access to Greek mercenaries from the Aegean. Where as the Egyptians were fairly useless outside of supplying naval personnel, the Persians had to garrison the country with over 20,000 troops a lot of which were mercenaries from Ebir-Nari, Babylonia and Assyria, maybe a significant amount of Persians and Medes as well.

[Azorica]

That's because my use of the term feudalism is not an exact meaning to Medieval Feudalism.

Feudalism and centralization are not mutually exclusive.

In my opinion our divergence in this subject is almost a semantic one. I have a tendency of considering "true" feudalism the act of land grant in exchange of service, in an almost client-style relationship, because I feel that including proto-feudal and tribal/tributary/vassal-overlord relationships of indirect rule to be a slippery slope that could lead to a "everything is feudalism" problem, because most pre-modern states, either more decentralized or centralized used forms of local government that could be considered to have feudalistic traits. Roman governors had great powers in their provinces, colonial powers appointed viceroys but they never had real control of the land as in de facto being able to use it at will. It is a feudal-like trait and could be considered by your point of view feudalism, although i would not consider it. That's why I apply the same for the persians since the satrap was in charge of the land as an administrator, had judge duties, controlled local officials, tribes and cities but was advised by a persian council that oversaw his stewardship.

So, for me, feudalism and centralization are mostly exclusive because the practice of feudalism chips away royal central power by creating petty kingdoms within the kingdom. However the depopulation, ruralization, demonetization and colapse of central bureaucracy in Western Europe following the colapse of the Empire and rise of the barbarian kingdoms made it the most efficient way, if not only way, of having a semblance of control in large states.

However I understand your point of view, merely disagree with it due to details and personal point of view and i'm at peace with this part.

CONTEXT!!!
For starters no, the PERSIAN PEOPLE were not highly urbanized. Iran at the time was not densely populated and had only a few towns, no massive cities and the population mostly lived in tents.

I must disagree with you there as I feel you are focusing too much on the Iranian Plateau which was indeed less urbanized and arid but even so possessed some important towns and cities such as Artakana. However I won't dispute that the city density in the region was lower than in others. But the Achaemenids ruled from Thrace to the Indus Valley and in Anatolia, Levant, Egypt, Tigris and Euphrates basin and Indus Valley had arguably large cities. We must analise in ancient standards: by those, the Achaemenids were a rather urbanized empire. More urbanized than them probably only Greece to to the nature of the settlements there, being city-states. True that they lost their most urbanized territories early in Alexander campaigns but that doesn't take their previous credit away and doesn't mean they didn't have any urban populations whatsoever outside the Mediterranean.

Third, by the time of Gaugamela Darius III did not have control of the western satrapies and the only lucrative province under his control was Babylonia. Not to mention that Alexander had captured his camp as well as his treasury.

I find it very hard to believe that a sovereign would take his entire treasury for a stroll when campaigning, as usually it was taken what was expected to be used as payment and for supplies and by the records of the treasury alone that was seized in Persepolis, one of the capitals of Achaemenid Persia, which was after Gaugemela, I also find hard to believe the King of Kings couldn't afford a new, larger army.

Those Greek mercenaries were the survivors of Issos but we don't even know how much there were. Not sure what nationalism has to do with this, or what you mean by it.
Roman recruitment was completely different from the Persians. But even in that case I am skeptical that the Romans raised 10 to 12 legions to fight some barbarians when in the 2nd Punic War they raised 8 legions for Cannae and Caesar had 8 to 10 legions to subdue all of Gaul.

What I meant about nationalism there is that since there was no proper concept of it, soldiers would flock to who could pay them, hence the greeks in persian service. Greeks happily slaughtered each other in petty disputes. Same with italics, gauls, germanics, amerindians, africans. They had no qualms in killing and/or enslaving each others in most cases, even though they shared a language and many cultural ties.

About roman recruitment, pre-marian recruitment was awfully close to persian. And greek. It was comprised of citizen-militias, which were to supply their own equipment and apart from the cultural significance of serving in the army, since they had something to lose (aka their lands) they would usually respond to summons. It was the norm in the ancient world. The macedonian phalangites were an exception as they were for all purposes professional soldiers, drilled and paid to do so.

Now about the context on why it is possible the Romans raised 10 to 12 legions against some barbarians. By the time of the Cimbrian Wars, the Republic had far more land, wealth and people than during the Punic but in spite of this they were in a war in North Africa, the Jugurthine wars. The barbarians were numerous and they had suffered disastrous defeats in Noreia and Burgindala. So, being Romans and wary now, they sent another larger army. Hilarity ensued as they were massacred and Rome was genuinely scared as it had pretty much no more eligible manpower. The important word being eligible. The Romans had manpower: landless, plague ridden peasants with no means to arm themselves. Here enter Gaius Marius, the scared senate approves the plan, funds the army, the reforms and the new model army of plague ridden peasants destroys the invaders with plague-like efficiency. Those were to be the Roman Legions we are so familiar with... That Caesar had in Gaul. Far superior in quality to levied soldiers, capable of long campaigns, professional, although more expensive, because standing armies are costly. This is when the roman recruitment diverges seriously from common ancient recruitment practices.

My point is that even in a developed state like Napoleonic France, they struggled to field more than 30,000 cavalry. They didn't even march as a single force for reasons of supply and had to march as separate columns. This was in a time of modern urbanization, much more advanced infrastructure, the beginning of modern industry, massive agricultural output, massive population growth and modern bureaucracies. How then could we justify the claim that the Persians could somehow field 40,000 cavalry as one army? What exactly would they forage in Mesopotamia? The horses wouldn't have anything to graze on and half the march is over the desert in central Mesopotamia where Sassanians and Romans struggled for a century.

Like I mentioned before, we can argue whether the persians fielded such a formidable force of cavalry at Gaugemela but we can hardly deny that they had the capability of raising such numbers and horses can be grain-fed by supply trains (in fact horses should have access to grains in their fodder to keep them healthy). Like I mentioned they had state-wide horse rearing and access to tribal levies and arguably far more land than Napoleonic France. Also reason that napoleonic corps marched in separate columns was because Napoleon took a page from both Alexander and Gaius and stopped the practice of cumbersome supply trains to favor mobility, dedicating more mobility to artillery and living off the land with limited supplies. That's why napoleonic corps were so fast in their age, caughting opponents by surprise. I agree though that agricultural output was far larger than ancient times due to introduced post-columbian species of plants and animals and more advanced field and crop rotation systems.

I doubt that the so called "Immortals" were actually a standing army, probably just the King's personal levy from the warriors on his direct land. The actual standing "army" must have been the couple thousand guard troops, the so called "companions" or "apple bearers".

According to the descriptions of Herodotus, the Immortals used spears with a round counter-weight, which resembled pomegrenates, which Alexander's troops associated with a an apple. There a real possibility that the "companions" or "apple bearers" were actually the "Immortals" and are widely regarded as being a standing force.

Babylonians were not a massive component of the Achaemenid army. Mostly it was composed of Medes and Persians but since the Persians lacked horses much of the cavalry was recruited from the Medes and Bactrians among other Iranic peoples. In the latter half of the Achaemenid period they began to resettle Persians, Medes, Bactrians, Babylonians and Assyrians in Ebir-Nari (Syria) and across Anatolia as part of military colonies. Which clearly indicates that these Iranic tribes were crucial in the empire's military power but also that they could make use of the Mesopotamians in a similar capacity. Though Anatolia was a rather self sufficient area since it had many useful Anatolian peoples which could be recruited as well as Ionians and access to Greek mercenaries from the Aegean. Where as the Egyptians were fairly useless outside of supplying naval personnel, the Persians had to garrison the country with over 20,000 troops a lot of which were mercenaries from Ebir-Nari, Babylonia and Assyria, maybe a significant amount of Persians and Medes as well.

Never said they were a massive component. Said they joined the ranks because the concept of "persianess" was rather vague and more flexible than, for instance, roman citizenship. Achaemenids used phoenicians, egyptians and greeks as sailors, levied infantry, archers and cavalry from persians, medians, assyrians and from tribal entities and hired mercenaries and the practice of military colonies was also common and adopted by both Hellenistic kingdoms and the Romans. Since it was pretty much self-sufficient in manpower terms, I would argue that maybe it was a way to "persify" the region?

[Ἀπολλόδοτος Α΄ ὁ Σωτήρ]

In my opinion our divergence in this subject is almost a semantic one. I have a tendency of considering "true" feudalism the act of land grant in exchange of service, in an almost client-style relationship, because I feel that including proto-feudal and tribal/tributary/vassal-overlord relationships of indirect rule to be a slippery slope that could lead to a "everything is feudalism" problem, because most pre-modern states, either more decentralized or centralized used forms of local government that could be considered to have feudalistic traits. Roman governors had great powers in their provinces, colonial powers appointed viceroys but they never had real control of the land as in de facto being able to use it at will. It is a feudal-like trait and could be considered by your point of view feudalism, although i would not consider it. That's why I apply the same for the persians since the satrap was in charge of the land as an administrator, had judge duties, controlled local officials, tribes and cities but was advised by a persian council that oversaw his stewardship.

So, for me, feudalism and centralization are mostly exclusive because the practice of feudalism chips away royal central power by creating petty kingdoms within the kingdom. However the depopulation, ruralization, demonetization and colapse of central bureaucracy in Western Europe following the colapse of the Empire and rise of the barbarian kingdoms made it the most efficient way, if not only way, of having a semblance of control in large states.

True, however while Satraps tended to be appointed and thus not hereditary owners of the land this doesn't preclude the existence of powerful, not fully cooperative, landowners under the satrap who can afford their own little armies.

The Sassanid Empire is a prime example because we know more about their internal dynamics than that of the Achaemenids. The great Houses had large estates, living in private palaces, scattered around the empire and over them there were satraps, yet on account of income from their estates they could have relatively large armies loyal only to them, complete with flags and sigils signifying their House, like in Medieval Europe, and thus had to be negotiated with. Naturally they didn't have hereditary satrapal rule, but Sassanid Shah was forced to appoint their members as satraps, or grant them military or other administrative posts at the expense of someone less powerful.

If I had to guess I'd say the situation was somewhat similar during the Achaemenids, the only difference being that there weren't any notably powerful single family that could threaten them, while for instance the Sassanids almost lost throne twice to the Mihranids.

[Azorica]

True, however while Satraps tended to be appointed and thus not hereditary owners of the land this doesn't preclude the existence of powerful, not fully cooperative, landowners under the satrap who can afford their own little armies.

The Sassanid Empire is a prime example because we know more about their internal dynamics than that of the Achaemenids. The great Houses had large estates, living in private palaces, scattered around the empire and over them there were satraps, yet on account of income from their estates they could have relatively large armies loyal only to them, complete with flags and sigils signifying their House, like in Medieval Europe, and thus had to be negotiated with. Naturally they didn't have hereditary satrapal rule, but Sassanid Shah was forced to appoint their members as satraps, or grant them military or other administrative posts at the expense of someone less powerful.

If I had to guess I'd say the situation was somewhat similar during the Achaemenids, the only difference being that there weren't any notably powerful single family that could threaten them, while for instance the Sassanids almost lost throne twice to the Mihranids.

Totally agree with you. Although it can be argued that the Achaemenids were a centralized state, it still was a aristocracy-based society. Could be more merit-based than contemporaries but it is fair to assume that court plots and power plays of nobles vying for influence and nominations was frequent and that incomes from their estates allowed them to have personal bodyguards, retinues and even whole companies. Satraps of both satrapies and their internal divisions more often than not tried to solidy their power base and since they were allowed to keep local troops, some even revolted. Darius I was plagued by such revolts, one of the reasons he reformed the system. It wasn't a perfect system, but more efficient than the government systems of the time.

Such occurrences happened with the Achaemenids, the Seleucids, the Parthians and the Sassanids, with the added bonus that both the Parthians and Sassanids having a more decentralized model, so what you describe about it, i feel its totally plausible and as Sassanids are not my "area of expertise" I'll your word for it

[Condottiere 40K]

Conscription was the the norm amongst the Greek city states, and early Roman Republic, one reason that despite military disasters that might have sunk anyone else, they could regenerate their armies.

Levee en masse may be a more local phenomenon, until the French Revolution; the feudalism institution of bring along entourages as part of regional magnates military service requirements still probably applies.

Going by the Old Testament, the Egyptians could establish granaries that could sustain their populace for seven years, so I presume the Persians could do the same, if they have enough cats.

[Azorica]

Conscription was the the norm amongst the Greek city states, and early Roman Republic, one reason that despite military disasters that might have sunk anyone else, they could regenerate their armies.

Levee en masse may be a more local phenomenon, until the French Revolution; the feudalism institution of bring along entourages as part of regional magnates military service requirements still probably applies.

Going by the Old Testament, the Egyptians could establish granaries that could sustain their populace for seven years, so I presume the Persians could do the same, if they have enough cats.

Conscription based on rather strict system of citizenship and landownership which makes it limited conscription or citizen-militias, which were common in ancient times, like i said before. They could regenerate as long as they had appropriate manpower pools. First country to introduce universal conscription was France (ok, near universal since it was male-only not full universal like Israel).

Not even tribes were all warriors and bringing entourages doesn't constitute feudalism. Feudalism is basically the practice to give up land grants in perpetua in exchange for labor or service, meaning economic/military support, which excuses the central government of expending in such domains by delegating to vassals at the expense of central power, usually due to lack of central bureaucracy. One reason it became widespread in Europe, apart from reasons I pointed before, is because makes raising cavalry and other retinues really cheap to the king. Cheap as almost free since the burden stays mostly on the vassal, although diminishing royal power towards landed nobility by granting military, legal and economic power to them, on their lands and court. These characteristics are absent from Achaemenid Persia. Nobles had estates and manors and all the panoply and were the major staffers of bureaucracy, for sure, but they lacked the authority feudal lords had. Satrapies fluctuated in autonomy and corruption and so on. Sometimes governors acquired influence, power and embezzled shinies and even revolted but all in all they were in simple terms state employees controlled by a central authority.

Lastly, kinda pointless comparison. We're talking supporting an army for a couple weeks, months at most, not an entire country for years. Creating or buying a surplus of food for a military campaign is not as hard, particularly if you have the financial means and infrastructure that the Achaemenids had.

[conon394]

Going by the Old Testament, the Egyptians could establish granaries that could sustain their populace for seven years, so I presume the Persians could do the same, if they have enough cats.

Roman era records but the number at 10-12 or longer in some cases years with loss and a not quality product to market.

[Cyclops]

There's an interesting discussion around the source of all these numbers. I have read proposals that they represent "total available manpower" and our Hellenic sources have simply transliterated available manpower for troops present.

Another argument is that someone has counted unit commanders, then found a unit of unusual size (in the Graeco-Persian wars the Immortals which had 10,000), and multiplied the number of commanders by an unusually large unit. In reality Xerxes or Darius levies probably read less like a USMC roll call and more like the reinforcements for the siege of Minas Tirith (Theoden brings 6,000 mixed cavalry, Imrahil shows up with at least 700 armoured elites but Forlong has only 200 axemen, and leaves most of his peeps at home, thanks fat guy).

The huge numbers of Xerxes armies have one obvious source, the awestruck spies captured by Xerxes and shown around his camp. they seem to have nailed the exact number of ships but maybe Xerxes "Grand-old-Duke-of-Yorked" them by marching his boys round a hill to make his forces look like three mill instead three hundred thousand.

[Condottiere 40K]

Well, generally speaking, feudalism is a set of obligations, an almost client style relationship.

As I recall, the Persians liked to count their contingents by corralling them in a set space, either per thousand or ten thousand.

One way to actually get an idea of at least size of a Persian expeditionary force, is trying to figure out the traffic through the pontoon bridge at the Hellespont.