In 1392 Bayazid organized a maritime expedition in the Black Sea ostensibly against Sinope. But the sultan put the Emperor Manuel at the head of the Turkish fleet. Therefore Venice thought that this expedition was directed not against Sinope, but against the Venetian colonies, south of the Dardanelles, in the Archipelago not a Turkish expedition, but a disguised Greek expedition, supported by Turkish troops. As a recent historian said, the Oriental problem of the end of the fourteenth century might have been solved by the formation of a Turko-Greek Empire. This interesting episode, evidence of which is in the archives of Venice, had no important results. Shortly after, the friendly relations between Byzantium and Bayazid came to an open break, and Manuel again turned to the West which for some time had been neglected.
Hard pressed, Manuel opened friendly negotiations with Venice. Bayazid tried to cut off Constantinople from its food supply. Such acute need was felt in the capital that, as a Byzantine chronicler said, the people pulled down their houses in order to get wood for baking bread. At the request of Byzantine envoys, Venice sent some corn to Constantinople.