Ertugrul (died c. 1280) was the father of Osman I, the founder of the Ottoman Empire. According to Ottoman tradition, he was the son of Suleyman Shah, leader of the Kayı tribe of Oghuz Turks, who fled from eastern Iran to Anatolia to escape the Mongol Conquests. This set off the chain of events that would ultimately lead to the founding of the Ottoman Empire. Like his son, Osman, and their descendants, Ertuğrul is often referred to as a Ghazi, a heroic champion fighter for the cause of Islam.