Murad, warned in time of the project, sent Khaïreddin pasha with a large army to Serres. The Greeks implicated in the plot were promptly executed, and Khaïreddin moved against Salonika. At the approach of the army, Manuel fled by sea to Constantinople. John Palaeologos was so frightened that he did not dare to receive in the imperial city the beloved son whom he had raised to the dignity of co-emperorship. Manuel then went to Lesbos, whose Genoese lord was his uncle by marriage. But the fear of Murad had reached the Aegaean Sea. The fugitive was turned away. Staking all upon the issue, Manuel went to Brusa and threw himself at Murad’s feet. The time was not yet ripe to destroy the Palaeologi. Murad pardoned Manuel, and sent him back to Constantinople. It was only after Manuel had presented a letter from Murad, confirming the fact that forgiveness had been granted, that the emperor of Byzantium dared to receive his son and heir within the walls of Constantinople.[353] Pressed by the Venetians, John made in 1375 the mistake of giving them, in exchange for three thousand ducats and the jewels which had been pledged for his debts after the visit to Rome, the island of Tenedos.[354] The strategic importance of Tenedos was so vital that the Genoese could not allow this island to fall into the hands of their rivals. It is an axiom as old as history that who holds Tenedos controls the entrance and exit to the Dardanelles. Until the Black Sea dries up and the wheat-fields of Russia fail to yield, there will be a ‘question of the Straits’. The news of this grant to Venice meant but one thing to the Genoese. There was feverish activity at Genoa. A fleet was manned, ostensibly for the purpose of maintaining the Levant colonies against the Turks.[355] Pope Gregory XI allowed the archbishop of Genoa to raise enormous sums by questionable means for equipping and increasing the fleet.[356] Instead of using this fleet to free the Aegaean and the Black Sea from the ever-increasing Turkish pirates, or to attack the Osmanlis, the Genoese admiral sailed to Constantinople. Aided by the Genoese of Galata and by Bayezid, Andronicus had escaped from the tower of Anemas. When the fleet arrived from Genoa, he gave to its admiral a golden bull, awarding Tenedos to Genoa.[357] To Murad he offered his sister in exchange for help.[358] The old story was repeated. After a month’s siege, Andronicus, by the aid of his Ottoman and Genoese supporters, entered Constantinople. His father and his two brothers, Manuel and Theodore, were imprisoned in the Tower of Anemas, where he and his son had been shut up for two years.[359] The foresight of Murad in regard to Andronicus was justified. While Andronicus was besieging Constantinople, John V managed to send word to the inhabitants of Tenedos to resist the Genoese and give themselves to the Venetians. If this were not possible, they were to abandon the island to the Turks rather than allow the Genoese to occupy it.[360]