Yakub I of Germiyan

Yakub I (died c. 1340) founded the Germiyan beylik in western Anatolia, centered on Kütahya. After submitting to the Sultanate of Rum, he became independent as the Seljuk state collapsed, and his domains stretched east to Ankara.

The contemporary al-Umari called him the most powerful Turkish emir, suzerain of his neighbours, with Byzantium paying him one hundred thousand gold pieces a year. The Catalan Company destroyed his army in 1304, and he twice besieged Philadelphia, which finally agreed to tribute around 1311. He died around 1340. He left a prosperous realm to his son Mehmed.