Yakup I of Germiyan

Yakup I of Germiyan (died after 1327) was the Turkmen founder of the Germiyanid beylik in Kütahya. He was the son of Kerimüddin Alişir and was succeeded by Mehmed I of Germiyan.

He refused to recognize the authority of Mesud II and swore allegiance to the Ilkhanids, which led to the establishment of his state. He gathered a significant amount of power and raided westwards, forcing the local Byzantine Empire to pay tribute for some time. He lost Alaşehir to a force of Byzantine mercenaries from Catalonia, but retook it in 1314. He also conquered Ayasluğ (present Selçuk) and Angir (present Simav). He established a number of foundations in Afyon.