After a year’s imprisonment, the emperor, through the wife of his jailer, succeeded in perfecting with Venetians residing in Constantinople a plan of escape. But its execution was deferred when John discovered that his sons, who were confined to separate rooms, could not be included in the rescue. Later, the efforts of the Venetians were renewed upon the solemn promise that Tenedos should revert to Venice. The plot was discovered. The Venetians, availing themselves of the lucky chance that a Venetian fleet had just arrived in the Golden Horn from the Black Sea, fled from Constantinople, abandoning John Palaeologos to his fate.[361] Andronicus IV was solemnly crowned in St. Sophia sole emperor of Byzantium. After two more years of imprisonment,[362] John and his sons succeeded in escaping in June 1379. They got across the Bosphorus, and took refuge with Bayezid, who was again watching the course of events at Scutari. Murad, still playing the game of pitting father against son, drove a hard bargain. Andronicus must be pardoned once more, and given the government of several cities, probably including Salonika.[363] John and Manuel, as a price for freedom and restoration to the imperial throne, agreed to pay an annual tribute of thirty thousand pieces of gold, furnish a contingent of twelve thousand soldiers to the Ottoman army, and surrender to the Osmanlis Philadelphia, the last Byzantine possession in Asia.[364] When the Philadelphians refused to assent to this shameful transaction, John and Manuel joined the Ottoman army and fought against their last Christian subjects in Asia to force upon them the Moslem yoke.[365] Thus did Murad hold to the lips of John Palaeologos the cup of humiliation, nay, more, of degradation, until he drained the last bitter dregs. We do not need to pass judgement upon John and Manuel. It is sufficient to say that they drank and did not die! The question of Tenedos brought Venice and Genoa into their most bitter conflict of the century. The Visconti of Milan were allied to the Venetians, while the Hungarians attacked them by land.[366] After initial successes, the great Venetian admiral Pisani was beaten decisively in 1379. The Genoese captured Chioggia, and held Venice at bay in her own lagoons. It was the timely arrival of Charles Zeno and the fleet from the Levant that saved the Adriatic republic.[367] In 1381, peace was made through the intermediary of Count Amadeo of Savoy, on condition that the Senate surrendered Tenedos to Amadeo, who guaranteed to demolish the fortress within two years. It was also a stipulation of the treaty of Turin that Andronicus IV be recognized as heir to John V.[368] Did the influence of Murad reach as far as the peace negotiations in the capital of far-off Savoy? The Count of Savoy fulfilled his promise. In 1383, the fortifications of Tenedos were rased, and the inhabitants of the island removed to Crete and Negropont.[369]