several large islands like Cyprus and Crete. Now the population under its control was limited to the few remaining cities in Byzantine possession, namely Thessalonica and Constantinople and the surrounding countryside, and the Despotate of the Morea. The immigration of Turks would be decisive in the survival of the Empire as it gave her most dire enemy, the Ottomans, a new power base, not in Asia but now in Europe. John V, 1354–1391 John V Palaiologos now had to face the serious threat the Ottomans posed to Byzantium. In the 1360s, the Turks continued to drive through Thrace, taking Byzantine, Bulgarian and Serbian settlements. Plea to the West Like his predecessors Alexios I Komnenos and Michael VIII, John V now turned to the Pope and offered the promise of a Union of the two Churches in the hopes of receiving military assistance. As a guarantee of compliance, John V offered his son, Manuel. In the past, Byzantium's cry for assistance were answered with mixed results — pillaging Crusaders would sack both friend and foe but the First Crusade had been largely beneficial and no doubt John V envisioned a repeat of such a Crusade. This time, however, the Papacy was unmoved by the calamity facing the Byzantine Empire. Fortunately for John V, he had other European connections — his mother was Anna of Savoy, and her nephew (being John V's cousin) was concerned for the safety of his Greek counterpart. Sailing from Venice in June 1366 with dreams of initiating yet another Crusade, Amadeo VI of Savoy arrived at and seized the fortress of Gallipoli from the Ottomans and handed it back to the Byzantines, hoping that this would stem the tide of Turkish emigration into Thrace. However, the Turks had by now firmly established themselves in Thrace. Amadeo and John spent much time between 1367 and 1369 thinking of ways to stave off defeat. Amadeo returned to Europe via Rome and brought with him Byzantine envoys. The Pope again was uninterested, but called for John V to visit him. In 1369, when the Ottomans finally captured Adrianople (though some sources indicate 1365), John V rushed to Rome and confessed his Catholic faith both privately and at a public spectacle. Nevertheless, in 1371 John V returned empty-handed, having humiliated himself and done nothing to improve the deteriorating situation in the Balkans. Ottoman vassalage of John V In 1371, the Serbs