Ankara Battle

The siege of Constantinople and the extensive Ottomans border reaching to Hungary are the reasons of the battle. The Hungarian king Sigismund requested help from Europe. As consequence crusaders united in order to get the Turks out of Balkans. They besieged Nigbolu fortress commanded by Dogan Bey. Bayezid I supported the fortress and defeated the crusaders. The victory of Ottoman army was considered very prestigious in Muslim countries.

Bayezid I in Anatolia

After the victory at Nigbolu, Bayezid returned to Anatolia and occupied Karaman in 1397 taking the cities of Karaman, Nigde and Aksaray and killed the ruler Alaaddin Ali Bey.

In 1399 he annexed the principality of Kadi Burhaneddin, the only obstacle for creating a centralised Anatolia.Then he controlled Dulkadirids under Memluke authority, enlarging the empire to the Euphrates in the east.

The rulers of the Principalities of Germiyan, Mentese and Aydin were against Bayezid as their lands were now Ottomans'. They needed Timur's help. On the other hand Baghdat's ruler Ahmet Celayir and Karakoyunlu's ruler Kara Yusuf took shelter in Bayezid when Baghdat was occupied by Timur. Consequently, Timur (Timburlane), powerful emperor in the central Asia and Iran quarreled with Bayezid and challenged with provocative letters and the battle became inevitable. Two armies met at Cubuk Field in 1402. The Battle of Ankara ended with Ottomans defeat and Bayezid I was taken prisoner.

After the Battle of Ankara ;

The principalities in anatolia re-established under Timur's protection, ending the Ottoman's centralisation in Anatolia. The conquest of Constantinople was delayed and Turkish progress in Rumelia stopped for a while.

The death of Bayezid I at Aksehir in 1403 caused "Fetret " (interregnum period) with the struggles of Bayezid's sons for controlling the territory which became hardly after the death of Timur.