weakening and collapse of the Anatolian Seljuk state by the end of the 13^th century, many beyliks emerged in Anatolia. The Ottoman state was one of these beyliks. Ärtogrul Gazi was a frontier beg who lived in Sögüt, with a cavalry of 400 at his command. Ärtogrul Gazi and his brother, Dündar Beg, had settled in Anatolia, but his other two brothers Gündogdy and Sungur Alp had returned to Horosan. After moving from place to place in Anatolia, Ärtogrul and Dündar Begs had finally taken Sögüt from the Byzantines. Later, the Anatolian Seljuk Soltan Alaaddin Keykubat granted Sögüt to them and Sögüt became their property. The Domaniç and Ermeni Mountains were given as pasture. Ärtogrul Gazi made Sögüt his home and died at the age of 93 in 1281.

After Ärtogrul Gazi, his son Osman Gazi replaced him. Gathering many Türkmen Begs around him, Osman Gazi established the state.

Osman Gazi was one of the three sons of Ärtogrul Gazi. He was distinguished from his brothers by his foresight and vigorous personality. After the death of his father, he succeeded in unifying the Türkmen Begs under his leadership. He was 23 years old when he came to power. He was a very handsome young Türkmen, tall, deep-chested, with heavy black brows over hazel-colored eyes and a Roman nose. He was broad-shouldered and the upper part of his body was longer than the lower part.

When Ärtogrul was on his deathbed, he announced his last testament: “ O! My Son! Every man will die. By the will of Allah, death has come at last to me. This state is entrusted to you. And I am entrusting you to Allah. Be just in all your affairs.”