I paste here the post I had made at Infracta some years ago for reference.
One event of potential interest is a plan by a French noble, Charles Gonzaga, Duke of Nevers, also Duke of Mantua and Montferrat (http://en.wikipedia.org/wiki/Charles_Gon…_and_Montferrat), to lead a revolution in the Balkan regions of the Ottoman Empire. He was distantly descended from the Palaeologus family and organised a meeting of rebel leaders from Dalmatia, Serbia, Bulgaria, Albania and Greece (especially Maina and Epirus) in a place called Kouki (or similar) in Albania on the 8th of September 1612. The rebels found allies in the Principalities of Wallachia and Moldova. They made plans to raise as many as 160,000 men across the Balkans and to take major Ottoman forts, whose garrisons were Christian and were in actual communication with the rebels, then march eastwards to lay siege on Adrianople and Constantinople. Many of the rebels apparently addressed in their letters the Duke of Nevers as Constantine Paleologus (To his most serene Excellency the Emperor Constantine Palaeologus, etc). Copies of some of these letters survive.
The Duke of Nevers at first commissioned five galeons and hired a small expeditionary force. A Capuchin priest named Joseph, later associated with Cardinal Richelieu, declared at the time a Crusade against the Ottomans in Spain, France and Germany. However, neither the Pope nor any of the European rulers endorsed the Crusade. Apparently both the Spanish Crown and the Venetians had competing interests in the area and disliked the idea. The Duke of Nevers nonetheless sent money to the rebels to organise their forces and obtain arms. He drew out a budget amounting to 2 million golden coins plus a million per year until Constantinople was taken. He requested and might have had pledges of 600,000 golden coins from the Spanish king and 300,000 from the Pope. He received pledges of ships from some rulers and also from the Knights of Malta whio indeed at around 1617 carried out naval raids against the Ottomans. Although the Duke of Nevers failed to gain the support of the Holy Roman Emperor or the Pope in person, he seemed prepared to take his chances with little help from the European rulers. Inexplicably, however, his five ships were destroyed by fire and he called off the expedition. Of all the rebel forces, apparently only a small force under a priest called Dionysios actually went ahead. They attacked the city of Ioannina in Epirus but, despite initial success, they were eventually defeated. Dionysios was captured and skinned alive. Maina was attacked by a large Ottoman army and was forced to come to terms. The revolution ended there, although the Duke of Nevers apparently continued to plot with local leaders until 1625 and hoped he might still be able to gain support to carry out his plans.
One option could be to assume that several Balkan regions were at flash point, with high levels of civil unrest. A Crusade had been called against Istanbul. Then if any of the European states joined that Crusade, a war could start between the Ottoman Empire and those states, which the German Emperor might potentially join. In this way there could be a perfectly historical scenario.
At this time point, in addition to the Duke of Nevers possibly aspiring to become a new Byzantine emperor, there were three mercenary captains under the name of Palaeologus in the pay of Venice: Ioannes Palaeologus, Theodoros Palaeologus and Constantinos Palaeologus. Obviously these also had the potential of becoming leaders of this revolution, especially had Venice joined the Crusade. Other captains of Greek mercenaries in Venetian service around this time included: Costas Rabdas, Markos Antonios Salas (Marcantonio Sala), Eustratios Nikephorakes, Martinos Gradanis, Demetrios Tarchaneiotes and Theodoros Karystinos.
I have found it easier to get information on the situation in Greece than in other Balkan regions.
Commerce and resources: Mademochoria, in exchange for their privileges, paid 220 kilograms of pure silver to the Sultan annually plus a capital tax in grain. Apart from the silver mines, the richest region in Greece appeared to be in Thessaly: raw cotton, wool, silk and dyed cotton – the latter being exported to Vienna, Leipzig, Dresden, Budapest and other regions, primarily in Germany. Wine was produced in Attica and in the region of the Peloponnese between Corinth and Argos and also in Cephalonia (under Venetian control). Mastic was produced in Chios. Olive oil in Crete, the Peloponnese and the Ionian Islands (Corfu, Cephalonia, Zante). I came across two named Greek merchants of that time: Nikolaos Mavrokordatos in Istanbul, a silk merchant. One of the city councillors of Athens at this time was a merchant named Kapetanakes.
Settlements: Among the larger settlements on mainland Greece were Thessalonika, Athens, Ioannina, Arta, Napoli di Romania (Nauplia), Patras, Negroponte (Chalcis), Larisa, Volos and Serres. The most significant fortresses were in Thessalonica, Ioannina and four fortresses close to each other in Corinth, Argos and Napoli di Romania (2 fortresses). Rhodes was also heavily fortified since the days of the Knights Hospitaller. The most heavily fortified city under Venetian control was Corfu, which was also the seat of the Venetian Admiralty.
Religion and schools: Except for the three autonomous regions, where entry to Muslims was forbidden by the Treaties, most towns in Greece had a mix of Muslim and Christian inhabitants. Athens at this time had a population of 15-16,000, with about 1000-1200 being Muslim. Parthenon had been converted into a mosque but remained otherwise intact. The vast majority of the Christian population was illiterate but Athens had some schools including a school of music. Greek schools began to be built at this time in other regions with donations from expatriate Greeks. There were Greek schools also in Istanbul and Venice at this period and theological schools in Istanbul, Ioannina and Mt Athos that had existed since Byzantine times. Some recorded historical priests of this period: Athanasios Vilerianos (1635), Philotheos, Hierotheos, Makarios, Ambrosios, Kallinikos, Theodoretos, Daniel, Kyrillos, Ioannikios, Christophoros, Liberakes Gerakares (1689). The bishop of Maina Neophytos was one of the Greek leaders of the 1612 movement. The Orthodox Patriarch in Constantinople/Istanbul was Parthenios III.
Government and diplomacy: The three autonomous regions were governed by councils headed by a prelate, somewhat in the style of the Italian city states. Mademochoria: capital Machalas (I believe ancient Stageira, the birthplace of Aristotle). Zagori: capital Kapesovo. Maina (Mani) had no capital, potentially Skoutari could be used, one of the bigger settlements. Greek diplomats serving under the Sultan in the late 17th C: Panagiotes Nikouses, Alexandros Mavrokordatos, Antonios Kremakes, Constantinos Giobanikes, Thomas Tarsias. City councillors of Athens of this period whose names could be used for diplomats or governors included: Stamates Paleologus, Giannis Paleologus, Ioannes Venizelos, Demetrios Venizelos, Leonardos Skleros, Demetrios Makolos, Panagiotes Kavallares, Stamates Chalcocondyles.
Rebels: Rebel captains of the 17th century in Greece: Chrysanthos Laskaris, Patrikios Phokas, Niketas Melissenos, Dionysios Ralles, Medikos, Stephanopoulos, Leonardos Philaras, Demetrios Niklos, Constantinos Poubalos, Gregorios Klinodes, Karales, Makrythanasis, Makropoulios, Karakitsos, Georgios Bernakiotes, Nikolos Tziobaras; Delphi/Lepanto: Libines, Skylodemos; Peloponnese: Panagiotaros, Kolokotrones, Kontobounisios, Chontrogiannes; Epirus: Lapas, Stournaris, Nikos Tsaras or Nikotsaras, Vlachavas, Kontogiannis, Christos Meliones, Zetros, Toskas, Syntekniotes, Theodoros Grivas, Poulios Drakos, Malamos. Rebel captains of the 16th century from the Peloponnese: Theodoros Agiapostolites, Michael Kalophonos, Nikolaos Mamonas, Theodoros Boukites.
I have been working on names also for the other factions.
Edit 1: By the way, the autonomous regions in Greece (1) Zagori (Zagorochoria), 2) Maina or Mani and 3) Mademochoria that included Mount Athos) are indicated in the online map I posted above. There were a couple of other regions (e.g. Souliotes) that I am not sure whether they had formal treaties with the Sultan. Zagori and Mani had small armed forces. Zagori and possibly also Mani provided small troops of Sipahi to Ottoman campaigns up to 1632 or 1638 but other than that had their own governments. There were no Turkish governors or delegates, in fact Turks/Muslims were prohibited entry according to a treaty that in the case of Zagori dated to 1430. Only Mani really rebelled against the Sultan, the others were more or less vassals, although individuals frequently fought as mercenaries mainly for Venice.
The map I posted has all the Venetian colonies of the time. The governors and some of the aristocracy were Venetian, but the soldiers were normally locals. Later in the 17th century Venice made attempts to capture more areas and succeeded for a time in capturing most of the south of Greece including Athens.
Edit 2: Actually, one possibility could be to have Mantua in the game and turn it into the Byzantine Empire if it captures Cosntantinople, and change the name of Charles Gonzaga to Constantinos Palaeologos if that happens. Just a thought - it doesn't have to be that way. The War of the Mantuan Succession (1628–31) was a peripheral part of the Thirty Years' War, in the course of which the Duke of Nevers found himself at war with Spain, the HRE and Savoy, with France as his only ally. Perhaps there is room for Mantua in the mod.