The founder of the Ottoman Empire is almost a historical black hole
Osman I gave his name to an empire that lasted until 1922, yet not one written source survives from his own reign. Ottoman chroniclers began recording his life more than a century after he died, so one historian calls the era a black hole. Even his name may originally have been Atman.
Osman, who died in 1323 or 1324, led one of many small Turkoman principalities, or beyliks, that sprang up in Anatolia in the later thirteenth century. His lay in Bithynia in northwest Asia Minor, well placed to strike at the weakened Byzantine Empire that his descendants would eventually conquer. The English word Ottoman comes from early spellings of his name such as Othoman.
His origins are wrapped in legend. Ottoman tradition says his father Ertuğrul led the Kayı tribe of Oghuz Turks west from Central Asia, fleeing the Mongols, and served the Seljuk sultan, who granted him the frontier town of Söğüt, where Osman was probably born around the middle of the century. Many scholars regard the Kayı descent and the Seljuk link as inventions of later court chroniclers to bolster legitimacy. The Karamanid historian Shikari even claimed Osman was a lowborn shepherd. One story places his birth on the day the Mongols sacked Baghdad in 1258; the historian Kemalpaşazade gave 1254 or 1255 and described him as Ertuğrul's youngest son, trained in riding, archery and falconry and guided by the Sufi sheikh Edebali.
His name is itself uncertain. The contemporary Byzantine historian George Pachymeres wrote Atouman or Atman, prompting suggestions that Osman first bore a Turkish name like Ataman and later adopted the more prestigious Arabic form, though Halil İnalcık thought that unlikely. The traveller Ibn Battuta called him Osmancık, Osman the Little, distinguishing him from the caliph Uthman.
He became bey around 1281, reportedly after a struggle with relatives including his uncle Dündar, whom he is said to have killed. The earliest event we can date is a clash at Bapheus around 1301 or 1302, when he beat a Byzantine force. He expanded from the barren country near modern Eskişehir into fertile Bithynia, absorbing local Byzantine lords by battle, purchase or marriage while avoiding stronger Turkish rivals.
Source: Osman I
