Key Facts
- Date
- June 9–11, 1359
- Castilian fleet size
- 128 warships
- Aragonese fleet size
- 10 galleys, 1 nau, several small craft
- First use of naval artillery
- Bombard mounted on Aragonese nau
- Castilian fleet origin
- Assembled at Seville, April 1359
Strategic Narrative Overview
The Castilian fleet arrived before Barcelona on June 9, 1359, with Peter I himself aboard. Peter IV of Aragon organized the city's defense alongside Counts Bernat III of Cabrera and Hug II of Cardona. Despite commanding only ten galleys, one nau, and small craft armed with crossbowmen and siege weapons, the Aragonese held off repeated Castilian attacks over two days. Crucially, a bombard mounted on the Aragonese nau was fired in combat, damaging one of the largest Castilian ships — the earliest recorded instance of naval artillery use.
01 / The Origins
The Battle of Barcelona arose from the War of the Two Peters, a conflict between Peter I of Castile and Peter IV of Aragon over territorial disputes and dynastic rivalries on the Iberian Peninsula. Peter I assembled a powerful fleet of 128 warships at Seville, bolstered by allied vessels from Portugal and Granada, and placed it under the Genoese admiral Egidio Boccanegra. The fleet sailed north along the Valencian coast in April 1359, seizing the Castle of Guardamar before appearing off Barcelona.
03 / The Outcome
The smaller Aragonese fleet successfully repulsed the Castilian assault, preventing the capture or destruction of Barcelona. The Castilian fleet, having failed to achieve its objective, withdrew without securing a decisive victory. The engagement demonstrated that defensive firepower could offset numerical inferiority, and the use of the shipborne bombard introduced a new dimension to naval warfare. The wider War of the Two Peters continued beyond this engagement.
Belligerents & Mobilization Analysis
Side A
1 belligerent
Peter I of Castile, Egidio Boccanegra, Ambrogio Boccanegra.
Side B
1 belligerent
Peter IV of Aragon, Bernat III of Cabrera, Hug II of Cardona.
Kinetic Engagement Axis
Scroll horizontally to view full axis. Events plotted relatively.