The Genoese, disregarding the terms of the treaty which permitted their colony at Galata, began fortifying and arming it. Their customs dues undercut the Byzantines and meant that as much as 87% of the revenue from control of the Bosphorus went to them instead of the empire. attempted to rebuild the shattered Byzantine navy in preparation for the war he expected to follow a reduction of Constantinople's own customs dues. He was able to borrow enough to construct 9 fair-sized ships and about 100 smaller ones before he lowered the rates and began siphoning off Genoa's income. When they did declare war, however, they were able to sink or capture his fleet by early 1349. The Genovese were forced to negotiate after major areas of Galata were burnt, including its wharves and warehouses, but the Byzantine Empire thenceforth was forced to turn to an alliance with the Republic of Venice for naval protection. This led to their involvement in Venice's 1350 war against Genoa, but Paganino Doria was able to force (and the twelve ships he had fielded) out of the war by a Pyrrhic victory off Constantinople the next year.