of the empire. As a co-sultan The details of the previous Mehmet–Musa alliance are not clear. Musa declared himself the sultan of the European portion of the empire, while Mehmet viewed Musa as his vassal. Musa besieged Byzantine Constantinople (modern Istanbul) as retribution for Manuel II Palaiologos's support for Süleyman during the previous battles between Musa and Süleyman. Manuel II Palaiologos turned to Mehmet for support, who betrayed Musa and set up a new alliance between himself and the Byzantines against Musa. In 1411 and in 1412, Mehmet's forces clashed with Musa's, and in both cases Mehmet was defeated. In 1413, Mehmet gained the support of Serbian monarch Stefan Lazarević and the bey of the Turkish Dulkadirids, as well as some of the generals in Musa's army. He defeated Musa's forces in the Battle of Çamurlu near Samaku (today Samokov, Bulgaria). Injured and trying to escape, Musa was spotted and killed on 5 July 1413. Aftermath Musa's death ended the Ottoman Interregnum. His brother Mehmet Çelebi became Sultan Mehmet I. However, in 1416, Sheikh Bedreddin, one of Musa's former allies (chief military judge, the kazasker), led an unsuccessful revolt against Mehmet I. Other events that may be viewed as the continuation of the interregnum were the two rebellions of Düzmece Mustafa Çelebi, another one of Beyazıt's sons who had been hiding in Anatolia. Mustafa was a fifth claimant to throne and he fought against both his brother Mehmet in 1416 and his nephew Murat II in 1421 unsuccessfully. Family Musa married two times: A daughter of Mircea I of Wallachia, married in 1403; A daughter of Carlo I Tocco, married in 1412; References 1413 deaths 15th-century people from the Ottoman Empire Ottoman princes Assassinated people from the Ottoman Empire Year of birth unknown People of the Ottoman Interregnum Pretenders to the Ottoman throne