| Conflict: | Battle of Ponza |
| Partof: | Aragon's Conquest of Naples |
| Date: | 5 August 1435[1] [2] |
| Place: | Island of Ponza, Tyrrhenian Sea |
| Result: | Genoese victory[3] [4] [5] [6] |
| Combatant1: | Duchy of Milan Republic of Genoa [7] |
| Combatant2: | Crown of Aragon |
| Commander1: | Filippo Visconti Biagio Assereto Jacopo Giustiniani [8] [9] |
| Commander2: | Alfonso V of Aragon King of Aragon John II of Aragon King of Navarre Henry of Aragon Prince Infante [10] |
| Strength1: | Genoese fleet |
| Strength2: | Aragonese fleet
|
| Casualties1: | 90 killed |
| Casualties2: | 600 killed ~100 Aragonese nobles captured 13 vessels lost |
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]
Joan II, Queen of Naples, died on 2 February 1435,[1] 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.[1] 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[4] who shortly after Queen Joan's death dispatched Francesco Spinola with 800 infantry.[5] The Duke of Milan (to whom the Republic of Genoa had lately submitted)[1] 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.[6] The royal galley of Aragon was compelled to strike,[15] and Alfonso V, King of Aragon was captured.[2]
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.[1] The Genoese were so utterly exasperated by the Duke's decision[4] that they started to rebel against him, drove out the Milanese garrison and overthrew his rule on 27 December 1435.[1]