The Kayı were an Oghuz Turkic ethnic group and a sub-branch of the Bozok tribal federation. In his Dīwān Lughāt al-Turk, the 11th century Kara-Khanid scholar Mahmud al-Kashgari cited Kayı as of one of 24 Oghuz tribes, saying that Oghuz were also called Turkomans.