Osman Gazi, one of the most important names in history, was the son of Ertuğrul Gazi and Halime Hatun.He was born in Söğüt in 1258. He took the power from his father Ertugrul Gazi and made his plans and made his struggle to establish a state. Osman Bey was the first Ottoman Sultan who founded the Ottoman Empire and gave his name to his state and family. He ruled the Ottoman state for 27 years.
Osman Gazi was married twice in his life and had 7 children from these marriages. His first wife’s name was Rabia Bala, and the second wife’s name was Malhun Hatun. Osman Gazi’s children were Orhan, Alâeddin Pasha, Melik Arslan Bey, Fatma Hatun, Çoban Bey, Hamid Bey, Pazarlı Bey. Mâl Hâtun was the daughter of Ömer Abdülaziz Bey, a Seljuk vizier, and the mother of Sultan Orhan. Rabî’a Bâlâ Hâtun was the daughter of Sheikh Edebali. Rabia Bala Hatun was also the mother of the prince Alaeddin.Some historical sources state that Osman Gazi was also called under different names. Some of these names were Kara Osman, Fahruddin and Mu’înüddin.
When Osman Gâzi conquered the Byzantine border cities one by one, the Byzantines, who were alarmed, prepared a raid in a wedding ceremony to kill him. Osman Bey responded to the Byzantine raid with a raid. He conquered Yarhisâr and Bilecik in 1299 and transferred the center of the principality to Bilecik and married Nilüfer (Holofura), daughter of Yarhisâr Tekfuru, who caused sedition, to his son Orhan. This date was accepted as the foundation year of the Ottoman Empire.Osman Gazi founded Yenisehir in 1301 near Bursa and transferred his sultanate center here. He was always loyal to those who helped him in all these conquests. He gave Eskisehir to his brother, Sultanonu to his son Orhan Bey, Yarhisar to Hasan Alp, Blecik to Sheyh Edebali and Inegol to Turgut Alp.The Ottoman Empire became completely independent in 1308 when the Seljuk State was ended by the Ilkhanid ruler Ahmed Gazan. Osman Bey gave the leadership of the principality to his son Orhan Bey in 1324.He died at the age of 67 before the conquest of Bursa in February 1324. Due to his will, Osman Bey’s body was taken from Sogut, where he was temporarily buried, and was buried in Gumus Kunbed in Bursa in 1326, 2,5 years later after his death.