Towards the end of the 14th century east of Central Anatolia was under the hegemony of a Turkmen leader named Kadı Burhaneddin. Bayezid I tried to conquer his territory without success. After his death and the short-term Timurid rule, Ottomans faced with a more powerful rival. In the 15th century tribes in the east, were united into a tribal confederation named Akkoyunlu (Turkish phrase meaning "White Sheep"). In 1473, Mehmed II defeated Akkoyunlu sultan Uzun Hasan in the Battle of Otlukbeli. After this battle all of the Central Anatolia and parts of East Anatolia became Ottoman possessions.