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

Osman I or Osman Ghazi was the eponymous founder of the Ottoman Empire. While initially a small Turkoman principality during Osman's lifetime, his beylik transformed into a vast empire in the centurie