Urban V was quick to use the prestige which he believed the adhesion of John Palaeologos had given him. He announced broadcast the happy consummation of his efforts, stating that the Byzantine emperor had done homage to the Vicar of Christ in St. Peter’s.[294] But letters sent during the same winter to the Greek clergy, urging them to accept the action of their emperor,[295] and other letters from his secret correspondence of this year, indicate how little faith he had in the Emperor’s sincerity or ability to fulfil his promises. Was the abjuration in St. Peter’s a farce, in which Emperor and Pope allowed themselves to trifle with holy things, each for the sake of his immediate advantage? John had hoped that his adhesion to the Roman Church would bring to him grants of money, ships, and men from the Latin princes, and that an army would rally around him to fight the Osmanlis. But not only did he return from France ‘with empty hands’, but he was detained at Venice because of debts owing to merchants. In vain he begged Andronicus to send the money for his release. The son who had four years before been charged with being party to his father’s imprisonment in Bulgaria was no more filial at this humiliating crisis. He answered that there was no money in the treasury, and that he could get nothing from the clergy. But his younger son, Manuel, brought from Salonika the ransom.[296] John Palaeologos returned to his capital poorer than when he left. He brought no help from Europe, and he had bound himself publicly by oath to an obligation which he had known he could not fulfil. He had broken faith with Murad, who during these years had been growing more and more powerful. There was nothing for him to do but to make himself tributary to Murad in order that he might enjoy ‘up to the end of his life’ his last possessions in peace.[297] Three years later, in 1373, when his ambassador John Lascaris failed in a second attempt to get aid from the Western princes,[298] the Byzantine emperor recognized Murad as his suzerain, promised to do military service in person in Murad’s army, and gave to him his son Manuel as hostage.[299] Urban died a few months after John’s visit to Rome. Gregory XI, who succeeded him in December 1370, had little hope of carrying on further negotiations with the Eastern Church; for the Greek ecclesiastics were stubborn in their determination to maintain the absolute independence of the patriarchate. The Genoese and Venetians were fighting bitterly in Cyprus. In 1371, Gregory made a strong appeal to France, England, Venice, and Flanders to co-operate with Genoa in saving the last Christians of the Holy Land.[300] There was no response.