The Pisans are lying in the Arno at the mouth of which lies Porto Pisano, the city's port, when the Genoese appear off Meloria, a rocky islet in the Ligurian Sea across from Livorno.

The Pisan fleet represents the whole power of the city, and carries members of every family of mark and most of the officers of state.

The Genoese, desiring to draw their enemy out to battle and to make the action decisive, arrange their fleet in two lines abreast.

According to Agostino Giustiniani, the first is composed of fifty-eight galleys, and eight panfili—a class of light galley of eastern origin named after the province of Pamphylia.

Oberto Doria, the Genoese admiral, is stationed in the center and in advance of his line.

To the right are the galleys of the Spinola family, among those of four of the eight companies into which Genoa is divided: Castello, Piazzalunga, Macagnana and San Lorenzo.

To the left are the galleys of the Doria family and the companies Porta, Soziglia, Porta Nuova and Il Borgo.

The second line of twenty galleys under the command of Benedetto Zaccaria is placed so far behind the first that the Pisans cannot see whether it is made up of war-vessels or of small craft meant to act as tenders to the others.

It is near enough to strike in and decide the battle when the action had begun.

The Pisans, commanded by the Podestà Morosini and his lieutenants Ugolino della Gherardesca and Andreotto Saraceno, come out in a single body.

The Pisan fleet advances in line abreast to meet the first line of the Genoese, fighting according to the medieval custom of ramming and boarding.

The victory is decided for Genoa by the squadron of Zaccaria, which falls on the flank of the Pisans.

Their fleet is nearly annihilated, the Podestà is captured and Ugolino flees with a few vessels.

Prisoners taken by the Genoese are in the order of thousands.

Among them is the poet Rustichello da Pisa, who will meet Marco Polo (captured during the Battle of Curzola) and write down the adventures of the Venetian explorer.

Pisa’s decisive defeat is a crippling blow to the maritime republic.