Köse Mihal
Köse Mihal (Ottoman Turkish: كوسه ميخال, lit. 'Michael the Beardless'; 13th century – c. 1340) accompanied Osman I in his ascent to power as a bey and founder of the Ottoman Empire. He is considered to be the first significant Byzantine renegade and convert to Islam to enter Ottoman service (see Nöker).
He was also known as Gazi Mihal (Ottoman Turkish: غازى ميخال) and Abdullah Mihal Gazi. He ruled over Harmankaya Kalesi (Ottoman Turkish: خرمن قيا قلعه سى).