Osman Bey, also called Osman Gazi عثمان غازى (Osmān Ġāzī) and it is also called Othoman. He was born in c. 1258 and died 1323 or 1324 ), He was the Leader of Kayi Tribe after his father death. And the founder of the Ottoman Dynasty. Othman is a Turkish state (this state first knows as ottoman Beylik or Emirate). Both the name of the dynasty and the empire that the dynasty established are derived from the Arabic form (ʿUthmān) of his name.
On the life of Osmān ghazi and on his tribe. Turk release a full Drama series (Kurulus Osman) which describe the past life of Osmān ghazi, his tribes and his Alps.