Ertuğrul Gazi

Ertuğrul Gazi (died c. 1280) was a Turkish marcher lord on the Byzantine frontier and father of Osman I, founder of the Ottoman dynasty. Little about his life is certain. An undated coin of Osman names him as Osman's father; the chronicles of his life were written a century or more later.

The chronicles differ over his father, but the official version names Suleyman Shah of the Kayı tribe. In that tradition the Kayı fled the Mongols westward, and after Suleyman Shah drowned in the Euphrates the tribe split; Ertuğrul went west with his followers. He served the Seljuk sultan Kayqubad I of Rum, receiving Karaca Dağ and later conquering Söğüt.

Besides Osman, tradition gives him two other sons. He died at Söğüt around 1280, and the town became the first Ottoman capital under Osman. Like his son, he was remembered as a ghazi, a warrior of the faith.