René, duc d’Anjou, was twenty-five in 1434 when he inherited from his brother Louis III of Anjou the French lands of Provence and Anjou, as well as a claim to the throne of Naples, offered to Louis by Angevin ruler Joanna II as her adoptive heir.

At her death on February 2, 1435, René, as her adopted son, had become titular king.

The rival claimant, Alfonso V of Aragon, who had been adopted as Joan’s heir in 1421 and disinherited by her two years later after attempting to seize power, readies an assault on Naples but while blockading the port of Gaeta, a key citadel from which to launch an attack, his fleet of twenty-five galleys is met by the Genoese ships sent by Duke Filippo Maria Visconti of Milan, who rules both cities.

In the ensuing battle off the island of Ponza, Alfonso is defeated and made prisoner, with many others, and sent to Genoa and then to Milan.