Battle of Ponza
Part of Aragon's Conquest of Naples
The surrender of Alfonso
Date 5 August 1435[7][6] Location Island of Ponza, Tyrrhenian Sea Result Decisive Genoese victory[1][2][3][4]
Belligerents
Duchy of Milan Republic of Genoa [1][2][3][4][5]	Crown of Aragon [6][2][3][5]
Commanders and leaders
Filippo Visconti Biagio Assereto Jacopo Giustiniani [1][2][5][8][9]	Alfonso V of Aragon King of Aragon (POW) John II of Aragon King of Navarre (POW) Henry of Aragon Prince Infante (POW) [6][1][3][9][10]
Strength
Genoese fleet: 3 galleys 13 vessels 2,400 soldiers [10][11][12]	Aragonese fleet: 11 galleys 14 vessels 6,000 soldiers [10][11][12]
Casualties and losses
90 killed[8]	600 killed[8] ~100 Aragonese nobles captured [7][10] 13 vessels lost[1][2]

The naval battle of Ponza was fought in early August 1435, when the Duke of Milan dispatched the Genoese navy to relieve the besieged town of Gaeta,^[13] which was currently under threat from the King of Aragon.^[14]

Conflict

Joan II, Queen of Naples, died on 2 February 1435,^[7] and by her will bestowed Rene d'Anjou with the crown of Naples.^[14] However, Alfonso, king of Aragon and Sicily, whom Queen Joan II had primarily adopted, claimed the succession, on the ground of this first adoption.^[7] Thus the successionist war between the House of Anjou and the House of Barcelona over the Kingdom of Naples ensued.^[12][13]

At this critical moment Rene d'Anjou was currently imprisoned in the Duchy of Burgundy^[15] and Alfonso of Aragon lost no time in stirring up his partisans in the Kingdom of Naples, whilst he himself sailed from Sicily with a large fleet to besiege Gaeta.^[14]

Gaeta itself was garrisoned by the Genoese^[2] who shortly after Queen Joan's death dispatched Francesco Spinola with 800 infantry.^[3][16] The Duke of Milan (to whom the Republic of Genoa had lately submitted)^[7] sided with the House of Anjou^[16] and dispatched a Genoese fleet^[13] in July under Biagio Assereto in order to relieve Gaeta.^[16] Alfonso immediately sailed against the Genoese fleet^[12] with superior numbers.^[15] The two fleets met near the island of Ponza and after a long and gallant conflict,^[15] which lasted for ten hours,^[13] the Genoese were completely victorious.^[4] The royal galley of Aragon was compelled to strike,^[15] and Alfonso V, King of Aragon was captured.^[6]

Aftermath

The siege of Gaeta was lifted,^[12] and the return of the Genoese fleet was met with a triumphant reception at Genoa.^[10] The King and all the noble Aragonese prisoners were then brought to Milan before the Duke,^[16] and with this one strike the war seemed already over.^[9]
However the King of Aragon managed to persuade the Duke of Milan to his side and against Rene d'Anjou, and was set at liberty with all other prisoners.^[7] The Genoese were so utterly exasperated by the Duke's decision^[2] that they started to rebel against him, drove out the Milanese garrison and overthrew his rule on 27 December 1435.^[7]