Following his release, Mehmet returned to Karaman as the bey of Karamanid state. In addition to his father's possessions, he was given a few forts by Timur and soon he began increasing his territory. During the
interregnum caused by Timurlane's devastations, Mehmet began occupying Ottoman and
Germiyanids (an ally of Ottomans ). In particular he captured
Kütahya the capital of Germiyanids. (The bey of Germiyan was the father in law of the former Ottoman sultan Bayezid I). The Ottoman interregnum ended in 1413 when
Mehmed I defeated
Musa Çelebi in Rumeli. After the victory, Mehmed I returned to Anatolia and defeated Karamanids in 1414. Mehmet II agreed to give all Ottoman territory (the forts given by Temur and the cities annexed by himself) back. Although he tried to infringe the treaty in 1415 he was arrested and had to swear an oath never to infringe again. He kept his promise and peace prevailed between the Ottoman Empire and the Karamanids during 1415-1422 period. But Mehmet II continued to fight in other fronts. He allied himself with the
Ramadanids (a small lordship) in
Çukurova (South Turkey, Cilicia of the antiquity) and began fighting against the
Dulkadirids, a vassal of
Egyptian Mamluks in south east Anatolia. In 1420, he was captured near
Kayseri by the Mamluks and was jailed in
Cairo,
Egypt. == Second reign and death ==