During the 11th century, the navy, like the Empire itself, began to decline. Faced with new naval challenges from the West, the Byzantines were increasingly forced to rely on the navies of Italian city-states like Venice and Genoa, with disastrous effects on Byzantium's economy and sovereignty. A period of recovery under the Komnenians was followed by another period of decline, which culminated in the disastrous dissolution of the Empire by the Fourth Crusade in 1204. After the Empire was restored in 1261, several emperors of the Palaiologan dynasty tried to revive the navy, but their efforts had only a temporary effect. By the mid-14th century, the Byzantine fleet, which once could put hundreds of warships to sea, was limited to a few dozen at best, and control of the Aegean passed definitively to the Italian and Ottoman navies. The diminished navy, however, continued to be active until the fall of the Byzantine Empire to the Ottomans in 1453.