When the chief of the Genoese forces which had captured Heraclia and were flushed with victory proposed to attack the capital, Cantacuzenus makes him abandon his design because he knew that it was defended by the emperor, who was the equal in wisdom and experience of any commander of the age.[74] It is in the same spirit of self-laudation that he declares that in the struggle with the Serbians before Salonica he had exterminated some by the simple terror of his name and others by his army.[75] [Sidenote: Reign of John after retirement of Cantacuzenus (1355 to 1391).] John occupied the throne after the retirement of Cantacuzenus for upwards of thirty-five years. A youth largely spent in selfish pleasures gave little promise that the young man of twenty-three would be able to cope with the difficulties by which the empire was beset. With the aid of his mother, Anne of Savoy, and of partisans whose only hope was in the patronage of the new ruler, he had succeeded in ridding himself of his elderly, respectable, and patriotic colleague. He had now to face the difficulties with which the empire was beset. Of these the dynastic struggle which still continued with Matthew, the son of Cantacuzenus, was soon disposed of. An agreement had been arrived at before the withdrawal of his father by which Matthew should retain the title of emperor and remain in possession of certain districts of the Rhodope mountains, and of the island of Lemnos. A few months later the island was exchanged for a lordship in the Morea. Shortly afterwards Matthew was made prisoner by the Serbians, delivered to John, and, after he had been kept for a while prisoner in Tenedos, abdicated and retired in 1358 to the Morea.