Osman I, also known as Osman Gazi, is the key figure in the establishment of the Ottoman Empire. He founded the empire around the late 13th century, uniting various Turkic clans in Anatolia through conquest and diplomacy. Osman’s leadership style and military strategies solidified a legacy that expanded over centuries. His name became synonymous with the empire itself, as the term "Ottoman" derives from "Osman." The empire flourished under his successors, evolving into a significant political and cultural power that would dominate parts of Europe, Asia, and Africa for over six centuries.