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. Reign 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 and mosques in Afyon. References Büyük Larousse, vol. 24, p. 12368, Milliyet Gazetesi Yayınları, "Yakup Bey I" Turkic rulers 1327 deaths People from Kütahya History of Kütahya Province Germiyan Year of birth unknown