The great anxiety of Cantacuzenus until, and even after, his abdication was to see his son recognised as emperor. Matthew, however, fell into the hands of John, who generously offered him his liberty on condition that he would renounce all claim to the throne. Cantacuzenus states that he counselled his son to accept this offer. After some hesitation he took his father’s advice. Articles of peace were accepted, and among the stipulations it was provided that Matthew might wear any buskin he liked except in purple. It was a relief to both parties when John saved himself from the reproaches of his father-in-law by leaving for Italy and Germany. His party appears to have increased in strength during his absence.[67] [Sidenote: Cantacuzenus submits and retires to Mount Athos, 1355.] He remained abroad for two years. On his return he encountered at Tenedos a Genoese adventurer, with a considerable number of followers, who was on the look-out for an island which he might seize as the Venetians had seized Chios. John proposed to employ the adventurer to aid him in becoming sole emperor. They came together to Constantinople, where the citizens had already risen in revolt against Cantacuzenus, who had in consequence to shut himself up in the Blachern Palace with a foreign guard. During the night John’s friends asked to be admitted at the postern of Hodegetria, pretending that they were merchants with a cargo of olive oil, and that the sea was rising and dangerous. They promised the guardians that if they were admitted half the cargo should be paid for the favour. They rushed the postern as soon as it was open, and two thousand men entered the city, took possession of the walls, and made a demonstration in favour of John. When morning broke, the Hippodrome was crowded with citizens, and the city in a tumult. Cantacuzenus apparently lost his head, entered the monastery of Peribleptis, and assumed the habit of a monk. He at once made submission to his young rival, asked and, after some weeks, received permission to retire to Mount Athos, and there passed nearly twenty-five years in the composition of his voluminous History. He died in 1380. Cantacuzenus, like his predecessors, looked to the West and especially to the pope to aid him in checking the progress of the Turks. Throughout the whole of his reign the attempts to obtain aid from the West and to bring about the Union of the Churches, two objects which had become inseparable, are constant. The zeal with which successive popes sought to obtain the Union found a ready response in Cantacuzenus.