While Timur was taking over Central Asia and India, the Ottoman-ruled zone was also growing. In 1389, Sultan Murad died in the Battle of Kosovo, killed by Serbian knights, but his son Bayezid was on hand. Bayezid had his brother killed and married a Serbian princess, thus eliminating two threats very quickly.
During 1390, Bayezid conquered on two fronts: continuing to expand in Serbia (Skopje, 1391) and also in Anatolia. He had a theological problem with his fellow Turks, since they were also good Muslims. There were two solutions: one, get Muslim scholars to issue fatwas justifying his wars; two, make his captured Christian soldiers fight the wars against Turks. He overwhelmed the smaller Turkish beyliks as his forces grew and grew with each victory. In 1394, Bayezid conquered northern Greece and the rest of Bulgaria; he crossed the Danube (though at that time the defenders won), and he began a siege against Constantinople.
Constantinople was a weak state at this time; its royalty were often fighting against each other, and they paid tribute to Murad and Bayezid. Manuel II Palaiologos spent a year as a hostage at Bayezid’s court, where he was forced to join the battle against Philadelphia, the last Greek Byzantine hold-out in Anatolia. That must have really hurt. When his father died, he fled from Bursa to secure Constantinople against other challengers, and Bayezid took it as rebellion.
The siege ran from 1394 to 1402. As it dragged on with no decisive action on either side, Manuel II took the radical step of traveling to western Europe to ask for Crusade help. He went through Germany, France, Aragon, Denmark, and even as far as England, where Henry IV (Shakespeare fans know him as Bolingbroke) held a joust in his honor. Pope Boniface IX preached crusade in 1396; King Charles VI of France sent six ships a few years later, but the main response was in Hungary, where the Ottomans had recently attempted to cross the Danube.
King Sigismund of Hungary led a Crusade of men from all over Europe, including a large French contingent (11,000) of knights and archers under John the Fearless, Count of Burgundy. Hospitaller Knights from Rhodes joined, and individuals came from as far away as Spain and England. The seeds of trouble lay, as usual, in the Crusaders’ disparate experiences and motivations. While the Hungarians were intent on defending their homeland, the French knights were seeking glory. The King of Hungary typically propounded cautious actions that took Bayezid seriously, while the French knights did not believe the Turks could actually challenge them and always sought to travel farther and take greater risks. Attack first, reconnoiter later; march all night, never mind what you’ll do when you arrive. Although Sigismund was the leader, the French knights were more numerous, so the army decided not to wait at Budapest, but to sally into Turkish-held territory.
It took them eight days to cross the Danube River at the Iron Gates, a narrow (but steep) point, with the help of Venetian ships and fishing boats. They easily took one Turkish-held town, and French knights raced ahead to seize the advantage at another fortress. Significantly, that action left them with about a thousand hostages, a mix of Turks and Christians.
The Crusaders set up a siege at Nicopolis, a fort held by Ottomans. The fortress was impregnable, perched on a high hill with steep sides. It was well-stocked for a siege, but the French knights were over-confident that Bayezid would not leave his siege of Constantinople and eventually Nicopolis would surrender; or perhaps they could break in with simple field-built ladders. Their camp did not build its own fortifications or keep an efficient watch on the countryside.
When Bayezid’s main force came near enough that some outriders saw and reported them, the Crusaders hastily made real battle plans but they had only a few hours’ preparation. In what turned out to be their worst mistake, they executed the thousand hostages. When the battle was over and Bayezid’s scouts were looking for dead kings among the bodies, they found the execution remains. Even in a more barbarous time, the slaughter of hostages constituted a war crime, and even in French eyes.
The Turks had taken many prisoners at this point, so Bayezid decided to take revenge. The most important prisoners were kept separately for ransom, while the youngest were sent to be slaves. Then the general mass of them were executed in a public ceremony while the Turkish army and the prisoners watched, like Richard the Lion-heart at Acre.
King Sigismund escaped on the battlefield, with the Master of the Hospital Knights. They got into a fishing boat and were rowed downstream to the Venetian ships. The rest of the Crusade’s energy was spent on ransoming hostages. One French eyewitness account of the battle came from a young man who was sent into slavery and did not return to France for 30 years.
King Sigismund held a number of titles including, eventually, Holy Roman Emperor. He never gave up his hope of driving the Turks away from Eastern Europe. To that end, he founded his own military order: the Order of the Dragon. Apparently, the name of “Dracula,” or Drakul, entered Transylvania naming tradition because of the Order of the Dragon!
However, Sigismund could not raise another Crusade, and the six ships sent by France to Constantinople helped very little. Bayezid resumed his siege. The only real relief for Constantinople was quite accidental: Amir Timur invaded the newly-won Ottoman lands of Turkey.
We shouldn’t be at all surprised by this outcome, even if the Crusaders were. With history’s hindsight clarity, we can see that earlier Crusade victories were heavily dependent on Turkish disunity. It was the onset of Turkish rule in the Holy Land that set off the Crusades in 1095; for the ensuing 300 years, the Turks had spent as much time battling each other and Egypt as the Crusaders. The three-way power split of Latins, Egyptians, and Turks always kept anyone from decisively ruling. As soon as the Muslims became unified, as they did under Saladdin, the Crusaders began to lose badly. Once the northern (Ottoman) Turks of Bithynia started taking over smaller rival Turkish zones, it was only a matter of time until any Crusade attempts would face a unified and much larger Muslim force.