In the 1070s, after the battle of Manzikert, the Seljuk commander Suleiman ibn Qutulmish, a distant cousin of Malik-Shah I and a former contender for the throne of the Seljuk Empire, came to power in western Anatolia. In 1075, he captured the Byzantine cities of Nicaea (present-day İznik) and Nicomedia (present-day İzmit). Two years later, he declared himself sultan of an independent Seljuk state and established his capital at İznik.
Suleiman was killed in Antioch in 1086 by Tutush I, the Seljuk ruler of Syria, and Suleiman's son Kilij Arslan I was imprisoned. When Malik Shah died in 1092, Kilij Arslan was released and immediately established himself in his father's territories.