Under the reign of John Palæologus, the progress of the Turks became more alarming. The emperor himself went to solicit the aid of the sovereign pontiff. After having, in a public ceremony, kissed the hands and feet of the pope, he acknowledged the double _procession_[69] of the Holy Ghost, and the supremacy of the Church of Rome. Touched by this humble submission, the pope protested he would come to the succour of the Greeks; but when he applied to the sovereigns of Europe, he could obtain nothing from them but vain promises. At the moment at which Palæologus was about to embark on his return to the East, he was arrested by his creditors, and remained thus during several months, without the pope or the princes he had come to solicit, and who had promised to assist him in the deliverance of his empire, making the least attempt to deliver him himself. Palæologus returned to Constantinople, to his divided family; and his subjects, who despised him, waited in vain for the performance of the promises of the pope and the European monarchs. In his despair, he at length formed the resolution of imploring the clemency of the sultan Amurath, and of purchasing by a tribute, permission to continue to reign over the wreck of his empire. He complained of this hard necessity to the pontiff of Rome, who caused a new crusade to be preached; but the Christian monarch beheld with indifference, a prince who had returned to the bosom of the Catholic Church, condemned to declare himself the vassal of infidels. The emperor of Byzantium and the head of the Church, by promising, the one, to arm the West in the cause of Greece, and the other, to subject the Greeks to the Roman Church, had formed engagements that they every day found it more difficult to fulfil. Whilst they were reciprocally upbraiding each other with not having kept their word, Amurath, who accomplished his threats better than the pope and the Christian princes did their promises, added new rigours to the fate of Palæologus, and interdicted even the repairing of the ramparts of his capital. Again the supplications to the sovereign were renewed, and again these supplications were passed on to the monarchs of Christendom; but they made no reply, or at most contented themselves with expressing pity for the emperor and people of Byzantium.