Germiyan, or the Germiyanids (Old Anatolian Turkish: كرميان; Turkish: Germiyanoğulları Beyliği or Germiyan Beyliği), were a dynasty that controlled parts of western Anatolia from c. 1300 to 1429. Germiyan first appeared in the 12th-century chronicles of Matthew of Edessa and The Georgian Chronicles when they fought against the County of Edessa and the Kingdom of Georgia. They reappeared in historical records of 1239 near Malatya, where they were tasked with suppressing the Babai revolt. The tribe relocated to western Anatolia with the encroaching Mongol invasion. During the reign of Yakub I (r. 1300–40), Germiyan gained sovereignty with the demise of the Sultanate of Rum and forged war with the neighboring Ottomans and the Byzantine Empire, which continued during his successor Mehmed's rule (r. 1340–61).
Amidst political tension caused by the neighboring Karamanids, Suleiman (r. 1361–87) married his daughter Devletşah Hatun to the Ottoman prince and future sultan, Bayezid I (r. 1389–1402). The process saw a major dowry payment that transferred much of the Germiyanid realm to Ottoman control, including the capital Kütahya. Yakub II (r. 1387–90, 1402–11) was initially on friendly terms with the Ottomans but eventually attempted to reclaim the former lands that were lost following his sister's wedding. He was jailed by his brother-in-law Bayezid I in 1390, and Germiyan wholly came under Ottoman control. Nine years later, Yakub escaped from prison and sought the protection of Timur (r. 1370–1405), who, after defeating Bayezid with the help of Yakub at the Battle of Ankara in 1402, restored Germiyan's former boundaries. In 1411, Kütahya fell to Mehmed II of Karaman (r. 1398–99, 1402–20), interrupting Yakub's reign a second time. His rule was reinstated by the Ottoman sultan, Mehmed I (r. 1413–21), upon the defeat of the Karamanids. Although Yakub meddled with the internal conflicts within the Ottomans, the triumph of Murad II (r. 1421–44, 1446–51) over his opponents forced Yakub to revert to amicable relations. Yakub lacked male heirs and left the sultanate to Murad II in his will shortly before he died in 1429.
