Timur destroyed the Ottoman army on the Çubuk plain outside Ankara in July 1402 and took Sultan Bayezid I alive; the sultan died in captivity within eight months and his sons fought each other for eleven years.
The Battle of Ankara was fought on the Çubuk plain north-east of the town in late July 1402 between Sultan Bayezid I and Timur, and it is the only battle in Ottoman history in which a reigning sultan was taken alive. Bayezid had spent a decade swallowing the independent Turkish emirates of Anatolia and grinding down the Balkans; Timur had spent the same decade conquering Iran, sacking Delhi and taking Baghdad, and the rulers Bayezid had dispossessed went to him for redress. The two met with a dispute over frontier princes that neither would settle by letter. The day is disputed: most modern accounts, and this archive, give 28 July, while an older tradition followed by several reference works gives 20 July.
The battle destroyed the Ottoman army in a day. Bayezid died a prisoner the following March, his four surviving sons fought one another for eleven years, and the beyliks he had annexed were handed back by the conqueror. It did not, however, destroy the Ottoman state: the family kept its European provinces, Mehmed I reunited the rest by 1413, and within fifty years his grandson took Constantinople.
Bayezid earned the name Yıldırım, the Thunderbolt, by moving faster than his enemies expected. He annexed Aydın, Saruhan, Menteşe, Germiyan and finally Karaman in Anatolia, ended the Bulgarian tsardom at Tarnovo in 1393, annihilated the crusade at the Battle of Nicopolis in 1396, and from 1394 kept Constantinople under a blockade that starved it for eight years. Each conquest made an exile, and the dispossessed emirs of western Anatolia found a patron in the east.
Timur had his own reason to look west. The Turkmen chief Qara Yusuf and the Jalayirid sultan Ahmad had taken refuge with Bayezid, and Timur regarded them as his to punish. The two rulers exchanged letters of studied insult, each addressing the other as an upstart; Timur took Sivas in 1400 and massacred its garrison, and in the summer of 1402 he moved on Ankara. Bayezid lifted the blockade of Constantinople and marched to meet him.
Bayezid's army was a coalition held together by conquest. Its core was the sultan's household: the janissaries, slave-soldiers of the infantry corps, and the sipahis of the Rumelian fief-holders who had fought his Balkan wars. Around them rode the Anatolian cavalry of the annexed beyliks, serving the man who had taken their lords' lands, and a contingent of Tatars settled in Anatolia. His Serbian vassal Stefan Lazarević brought a body of armoured horsemen who were, by every account of the battle, the best troops on the Ottoman side.
Timur's army was larger, rested, and built around mounted archers who could shoot and manoeuvre together for hours, with an elephant corps brought back from the Indian campaign. He also chose the ground. He reached Ankara first, drew the Ottomans out by threatening the town, and had the water of the Çubuk stream diverted into a reservoir so that Bayezid's men arrived at a position without wells. The Ottoman commanders are said to have advised waiting on the defensive; Bayezid attacked.
The fighting began early and lasted most of the day. Timur's wings enveloped both Ottoman flanks while his centre held, and the first collapse came not from the pressure but from within: the Anatolian sipahis of the annexed beyliks, seeing their own former lords in Timur's line, rode across to them, and the Tatar contingent went the same way. The Ottoman left under Süleyman Çelebi broke; Mehmed Çelebi, commanding in the rear, cut his way clear.
The Serbs under Stefan Lazarević fought their way into the Timurid ranks three times, an effort Timur is reported to have admired aloud, and they got one of the sultan's sons and the treasury off the field. Bayezid stayed with the janissaries on a hill until nightfall, then tried to break out with a few hundred horsemen. Timur's riders ran him down in the dark. The corps that had made the Ottoman army — the janissaries and the Rumelian sipahis — were destroyed where they stood.
Timur kept the captive sultan with his camp and treated him, by the Timurid account, with the courtesy due a defeated ruler. Bayezid died on 8 March 1403, eight months after the battle, having been carried across Anatolia with the army; the sources disagree over whether illness or his own hand killed him. The story that he was displayed in an iron cage grew later and is not in the earliest accounts: it comes through Timurid and European retellings that wanted the humiliation to be visible, and Christopher Marlowe made it famous two centuries afterwards.
Timur spent the winter dismantling what Bayezid had built. His grandson sacked Bursa, the Ottoman capital in Asia, and burned the dynasty's tombs; the Knights Hospitaller were stormed out of Smyrna in a fortnight; and the beyliks of Aydın, Saruhan, Menteşe, Germiyan and Karaman were restored to their old houses as Timurid clients. Then he turned east for a campaign against China and died on the road in 1405.
Bayezid left four sons with armies and no rule to divide them. Süleyman held Edirne and the European provinces, İsa held Bursa, Mehmed held Amasya in the north-east, and Musa was released from captivity to fight for the family's Balkan lands. The eleven years that followed are called the Interregnum, and they were a real civil war: İsa was killed about 1406, Musa had Süleyman killed in 1411, and Mehmed finally beat Musa at Çamurlu in July 1413 and ruled alone.
Two things kept the state alive through it. The Ottoman timar system in the Balkans, which paid cavalrymen with the revenue of land they did not own, survived the collapse of the dynasty's authority because the fief-holders had every reason to keep it working. And the Christian powers around them could not agree to finish the job: Byzantium, Venice, Hungary and the Serbian despotate each backed a different brother, and the despot Stefan Lazarević, freed from Bayezid's overlordship, used the interval to make himself a genuinely independent prince at Belgrade.