Two years later, the good understanding between Mahomet and the emperor was interrupted by an incident which is creditable to Manuel. A Turkish pretender who claimed to be Mustafa, the elder brother of the sultan, who is supposed to have been killed at Angora, aided by a body of Wallachs, attempted to dethrone Mahomet. They were attacked and beaten back and then took refuge in Salonica. Manuel declined to give them up, but promised that he would prevent the pretender and the leader of the Wallachs from making further attacks upon Mahomet. To accomplish this, he sent the pretender Mustafa to the island of Lemnos and imprisoned the chief of the Wallachs in the monastery of Pammacaristos in Constantinople. But Mahomet would not be satisfied with any punishment less than the death of the pretender, and from this time ceased to trust Manuel. Nevertheless, when, in 1420, the sultan was in passage through Constantinople towards his Asiatic possessions, Manuel behaved loyally. All the members of his council, says Phrantzes,[128] advised the emperor to seize him. Manuel refused and declared that, though the sultan might violate his oath of friendship, he would rather trust to God and respect his own. On Mahomet’s return to Europe through Gallipoli, the council again urged the emperor to capture him. Again, however, he refused, and sent a trusty general to escort him from the Dardanelles to Adrianople. A short time after his arrival, in 1420, Mahomet died. [Sidenote: Reign of Murad, 1420–1451.]