After a Venetian attack on Genoan Galata in 1296, Andronikos II decided to come to the aid of his ally Genoa.

During the course of the campaign, various Genoese possessions in the Mediterranean and the Black Sea were captured, including the city of Phocaea.

In July 1302, a Venetian fleet with twenty-eight galleys arrived before Constantinople itself, and staged a demonstration of force: before the eyes of the Byzantine capital's inhabitants, the admiral Belletto Giustinian flogged the population of the island of Prinkipos, including refugees from Asia Minor who had fled the Turkish advance there, which the Venetians had taken prisoner.

According to its terms, the Venetians returned most of their conquests, but kept the islands of Kea, Santorini, Serifos and Amorgos, which were retained by the privateers who had captured them.

The failure of the Byzantines to combat the Venetian threat demonstrated the problem with Andronicus's disbandment of the fleet.