Osman I or Othman I or Osman Gazi (1258 – 1326) Ottoman Turkish: Sultan Osman Ghazi, Turkish: Osman Gazi or Osman Bey or I. Osman, Osman Gazi Han), nicknamed "Kara" for his courage, is the leader of the Ottoman Turks, and the founder of the dynasty that establishes and rules the Ottoman Empire.

The Empire, named after him, will prevail as a world empire for over six centuries.

Osman announces the independence of his own small kingdom from the Seljuk Turks in 1299.

The westward drive of the Mongol invasions has pushed scores of Muslims toward Osman's Anatolian principality, a power base that Osman is quick to consolidate.

As the Byzantine Empire declines, the Ottoman Empire rise sto take its place.