Here's what's bugging me:
- I can think of no reason that Byzantine foot archers would not be almost equal to or even superior to English longbowmen.
The Byzantine and English archers never faced each other in battle, but some Byzantine areas like Crete and the area around Trebizond had very strong archery traditions. The Byzantine army had a fairly professional archery corps. The Byzantine infantry bow was a sophisticated composite bow which should have shot better, for a given draw weight and draw length, than the English longbow -- and as far as I know, their draw weights were not vastly different. In addition, as far as I know, the Byzantine foot archery corps was not wiped out at Manzikert like their cavalry corps (in fact, I’ve read claim that the fact that Romanos Diogenes wanted a mobile all-cavalry army and didn’t bring along foot archers was why Manzikert was such a disaster). Why wouldn't Byzantine foot archers be comparable to English?
- The Byzantines found Frankish crossbows quite impressive and scary
Anna Komnene's account of the crossbow in the Alexiad and Nicholas Mesarites account of an encounter with crossbow-wielding pirates portrays the invention as deadly, bordering on diabolical. Neither of these weapons would have been very advanced crossbows -- Anna Komnene's account takes place as the first crusade arrives in Byzantine lands in 1096, and Mesarites' account explicitly describes the weapon as having an all-wood prod without bone or sinew -- although perhaps it was a crossbow explicitly designed for maritime use, and a laminated prod was avoided to enhance resistance to the elements?
- English longbowmen did not find crossbows very scary
I mean, no doubt some of them died agonizing deaths with crossbow quarrels in their lungs, but overall, English archers were generally regarded as outmatching even the finest Genoese crossbow-wielders. There may have been times when the crossbows did well, and some times when they did poorly but it was attributable to circumstantial factors (all of the factors at Crecy like elevation, rain, sun, shields left in baggage trains, etc), but on the whole, I think that the English regarded archery was one of their big advantages. The cases of English longbows matched against Genoese crossbows take place in the crossbow’s heyday, in the hands of its most accomplished wielders, with (presumably) more advanced crossbows than those encountered by Nicholas Mesarites or Anna Komnene’s friend Marianus.
So I’m wondering how this would work. Were English archers simply better than their Byzantine counterparts? If so, why? Were the Byzantine chroniclers psychologically shocked by the power of an individual crossbow’s shot, but not taking into account how its slow rate of shot would give it disadvantages in the heat of battle compared to regular archers?
One of the more out-there hypotheses I’ve seen is early medieval crossbows were actually more effective than later ones. The idea is that primitive crossbows had long, longbow-like prods, with a long powerstroke like the crossbows of the Han dynasty. Later crossbows had stronger, smaller prods with a shorter powerstroke. Earlier crossbows would have required a lot of space to each user’s side, making them impractical for massed use, but generally gave more energy per draw weight. However, I think this is a fairly loopy hypothesis without any evidence that I'm aware of.
Another possibility is that the Byzantine archers were specialized to defeat Magyar or Turkish-type horse archers -- enemies with little armor or horse barding. Range and volume of ammunition was a priority over penetrating power, so light arrows were preferred. Thus the penetrating power of the crossbow came as a shock compared to the light arrow-using archers. The English archers used heavier, more penetrating arrows, which didn’t go as far and couldn't be carried in as large numbers, but could pierce most armor.