The Seljuks originated from the Oghuz Turks, who in the 9th century lived at the edge of the Muslim world on the Kazakh Steppe. When Seljuk, the leader of the his clan, had a falling out with the leader of the Oghuz tribe, he left the Oghuz tribal lands and set up on the west bank of the Syr Darya river. Around 985 CE, Seljuk converted to Islam.