A naval battle

The ships' flags appear to be those of Pisa and Genoa and it has traditionally been assumed that the scene depicts the Battle of Meloria, fought between those two cities on 6 August 1284. The long rivalry between them erupted in 1282 in a sovereignty dispute over the islands of Sardinia and Corsica. When the two forces met off Meloria, the Pisans, commanded by the Podesta Morosini, were lying in the river Arno; their fleets represented the entire power of the city and carried members of every family of mark and a host of officers of state. However, they were outnumbered by the Genoese who drew them out to battle and then out-manoevered them in combat: the ensuing Genoese victory was decisive, forever destroying Pisa as a naval power. Two years later the Genoese were able to take the Porto Pisano.