Aragonese Crusade Angevin invasion of Sicily The Battle of the Gulf of Naples was a naval engagement during the War of the Sicilian Vespers.

The war expanded when the Kingdom of Aragon intervened on the Sicilians' behalf, landing an army on Sicily and successfully forcing the Angevin king, Charles of Anjou, to evacuate the island.

[2] While Aragon occupied Sicily, Charles of Anjou worked to rebuild his kingdom's naval power, as he had lost a number of ships during his evacuation of the island.

Frustrated by the poor performance of his navy, Charles of Anjou accelerated his naval buildup, replacing his existing captains with new commanders whom he hoped would be more aggressive.

Leaving 10 of his ships at Castellammare, Lauria then led his main force of 20 galleys to the mouth of Naples' harbor, taking up positions just outside the city's breakwater.

[2] While the battle had been an Aragonese success, the loss of Charles' fleet did not overly impact the naval balance of power in southern Italy, as the Angevins still maintained a sizable numerical advantage in ships.