The Republic of Pisa is defeated in the Battle of Meloria by the Republic of Genoa, thus losing its naval dominance in the Mediterranean.

The Republic of Pisa was an independent state existing from the 11th to the 15th century centered on the Tuscan city of Pisa. It rose to become an economic powerhouse, a commercial center whose merchants dominated Mediterranean and Italian trade for a century, before being surpassed and superseded by the Republic of Genoa.

The Battle of Meloria was fought near the islet of Meloria in the Ligurian Sea on 5 and 6 August 1284 between the fleets of the Republics of Genoa and Pisa as part of the Genoese-Pisan War. The victory of Genoa and the destruction of the Pisan fleet marked the decline of the Republic of Pisa.

The Republic of Genoa was a medieval and early modern maritime republic from the years 1099 to 1797 in Liguria on the northwestern Italian coast. During the Late Middle Ages, it was a major commercial power in both the Mediterranean and Black Sea. Between the 16th and 17th centuries, it was one of the major financial centres of Europe.

August 6 is the 218th day of the year in the Gregorian calendar; 147 days remain until the end of the year.