The French camp is hit hard by an epidemic of dysentery on the heels of the naval loss.
Philip himself is afflicted.
The heir to the French throne, the future Philip IV, opens negotiations with Peter for free passage for the royal family through the Pyrenees,.
The pass around the massif of Albères (five hundred and sixty-eight meters) was the main route through the Pyrenees in Antiquity.
The Romans called it the Summum Pyrenæum.
It had since been superseded by the Col de Perthus one kilometer to the northeast.
The Aragonese troops, saving promised to leave the passage to the French king and his family, content themselves with attacking the retreating French army, decimated by dysentery.
Peter entrusts the vanguard to Ramon de Montcada and his Almogàvers, who massacre the fatigued French but spare the royal family.
This first attack is followed up by a second attack by Roger de Lauria, the admiral of the fleet which had defeated the French at Les Formigues and had then disembarked to fight on land.
The result of all this is a rout: the French are decimated further and it is a complete Aragonese victory.
According to the chronicle of Ramon Muntaner, the festivities of celebration last eight days in Barcelona.
