Two empires were expanding during the late 1300s; inevitably, they collided. In 1400, Timur’s Turko-Mongolian army based in Samarkand invaded the region we know as Turkey, and we’re almost to the point where we can call it that, but not quite. It was Ottoman unification that made “Rum” into Türkiye, and Timur’s invasion was the last meaningful check on Ottoman power.
Timur occupied (and destroyed) the city of Sivas in central Anatolia, not far from Ankara. In the next year, Bayezid pulled away from his siege of Constantinople and the armies moved closer until they met at Ankara.
Ankara’s history as a town goes back to 2000 BC, anyway; it is a rich archaeological field with Hittite and Phrygian sites. In Roman times, it was called Ancyra, which came into most European spellings as Angora. It sat at a major crossroads for travel north and east into the Roman hinterlands. We remember it best for its production and export of thick, soft fur in goats, rabbits, and cats.
Bayezid brought to the battle an array of all of the forces the Ottomans had been collecting: Serbian knights, with other conquered Christian forces; infantry and cavalry from the Turkish beyliks he had been conquering, perhaps some who were native to the Ankara region; and Janissaries, at that time numbering several thousand but with elite training and high morale. I couldn’t find an estimate for his overall numbers at this battle. His numbers at Nicopolis were reported at 60,000 by a contemporary, but modern historians guess it was more like 20,000. So perhaps he had 20,ooo to 40,000 at Ankara? Bayezid’s sons were all present, acting as his generals.
Timur’s army was mostly cavalry, according to the Mongol-Tatar tradition. However, since his conquest of Delhi, he had picked up elephant-mounted troops as well. Estimates of his numbers vary; this is a problem with all of the histories of the time. Some sources reported that King Sigismund’s Crusade was as large as 90,000, which seems highly unlikely. In the same way, some estimates of Timur’s strength seem improbably high, like his contemporary historian Ahmad ibn Arabshah’s estimate of 800,000. But Timur’s low estimate is larger than the Crusaders’ highest one: realistically, he may have had 150,000 troops, with his 32 elephants and their herds of horses. He vastly outnumbered Bayezid, in other words. Timur’s men had traveled in a more leisurely way, since the defending forces were tied up in a siege, so by the time he went out to meet Bayezid, his horses and men were well-rested.
Bayezid’s troops, on the other hand, had hurried so they were tired when they arrived. They got no respite but had to give battle immediately on July 20, 1402. There was one last major problem, reminiscent of earlier Crusader battles: the enemy dug some canals to divert streams away from the Ottoman camp. Thirst is an implacable enemy.
The Serbian knights held up the best against Timur, who depended mostly on archers whose arrows did not pierce plate armor. The Janissaries were completely wiped out. Some of the Turkish horse-soldiers on the Ottoman side defected to Timur, whose style of battle probably appealed to them more anyway. Bayezid and one of his sons, with a few hundred horsemen, fled into the mountains, but Timur had the numbers to surround the region. He was captured after 3 months. Some of the Ottoman army fled to Venetian ships (probably left from the Crusade) and made it to safety, preserving a core of Ottoman power.
Timur’s forces kept marching to the Aegean Sea, also destroying Smyrna where the Hospital Knights had a fortress. But he didn’t set up a new capital or otherwise permanently take over Turkey. He left Anatolia very soon because one of his vassals had rebelled by attacking Baghdad.
Timur was making plans to assault China, in an attempt to restore the Yuan Dynasty, when he died. His body was embalmed in rose water and sent back to Samarkand, while his successors started to contest with each other. After several grandsons’ short reigns, the power went to Timur’s youngest son Shah Rukh, then to Rukh’s son Ulug Beg.
It wasn’t nearly as neat for the Ottomans. Bayezid’s death left five sons who all had powerful connections as generals. Their civil war lasted until 1413, spilling into Thrace and Serbia and entangling Constantinople’s poor Emperor Manuel. In the end, Mehmet I crowned himself Sultan and began minting coins with that title. He rebuilt the Janissaries and ruled from the European-side capital of Edirne. From this time, it’s proper to refer to Anatolia as Turkey, and it was never again seriously divided.