In 1386, the Venetian Republic successfully agreed to purchase Corfu, and in this regard, Butrinti became the defense of this state in the east. Venice's dominance in the Mediterranean was based more on trade, and therefore the republic relied heavily on its strong fleet. To secure maritime trade routes between the Adriatic and Aegean Seas, and fearing an increasingly strong and aggressive Ottoman Empire, the Venetians launched military campaigns to reinforce coastal castles at their colonial pivot points in Greece. Butrinti, as the northernmost of the group of Ionian coastal fortifications, was no exception to this scheme. The most impressive defensive structure outside the old Butrint fortifications and the most prominent Venetian creation is the Venice Triangular Fortress on the banks of the Vivari Canal. Built after 1490, the fortress was created primarily to protect Butrint fishermen. Created according to a unique project, only a little similar to the architecture of medieval Europe, the shape of the fortress may have been partially dictated by the shape of the island on which it was built.