How a local massacre in Constantinople triggered the final collapse of Byzantine naval power
When Genoese residents slaughtered Venetians in Constantinople in 1296, the Byzantine Emperor Andronikos II Palaiologos chose the wrong side. By arresting survivors rather than protecting them, he ignited a conflict that exposed his empire’s fatal weakness: a total lack of naval defense, leading to the end of Byzantine maritime supremacy.
The Byzantine–Venetian War of 1296–1302 was an extension of a broader struggle between Venice and Genoa over Mediterranean trade. Tensions exploded in 1296 when Genoese residents in Constantinople destroyed the Venetian quarter and killed many civilians. Emperor Andronikos II, bound by an alliance with Genoa, arrested the Venetian survivors, including the bailo Marco Bembo. This violation of the 1285 treaty prompted Venice to demand reparations and launch a naval campaign, though the Emperor initially sought to avoid full-scale war.
Hostilities intensified after Venice concluded its conflict with Genoa in 1299. Free to focus on the Byzantines, the Venetian fleet—bolstered by privateers—began seizing islands in the Aegean Sea. These territories, many of which the Byzantines had reclaimed from Latin lords only two decades earlier, proved easy targets. The vulnerability of these islands highlighted the catastrophic consequences of Andronikos II’s earlier decision to disband the Byzantine fleet, a move that left the empire unable to project power or protect its maritime borders.
The war reached a grim climax in July 1302, when a Venetian fleet of twenty-eight galleys appeared before Constantinople. Admiral Belletto Giustinian staged a brutal demonstration of force, publicly flogging prisoners from the island of Prinkipos in view of the capital's inhabitants. This humiliation forced the Byzantine government to sue for peace. The treaty, signed on 4 October 1302, required the Byzantines to compensate Venice for the 1296 massacre and concede several Aegean islands to the privateers who had captured them. Despite later attempts by Andronikos II to rebuild his navy, the era of Byzantine naval dominance was effectively over.
