The Battle of Barcelona (June 9–11, 1359) was a naval engagement fought in the coastal region of Barcelona, Spain, between the navies of the Crowns of Aragon and Castile, during the War of the Two Peters. A number of months beforehand, a large Castilian fleet had been assembled at Seville by order of the King of Castile, Peter I. Consisting of 128 warships including royal vessels, ships from the King of Castile's vassals, and several others that had been sent by the Castilian-allied monarchs of Portugal and Granada, this large fleet had been entrusted to the Genoese admiral, Egidio Boccanegra, who was seconded by two of his relatives, Ambrogio and Bartolome.