Only a few days earlier, on 18 January 1812, Eroles' 4,250-man force had wiped out an 850-strong French battalion of the 121st Line Infantry Regiment at the Col de Balaguer, southwest of Tarragona. Only the French commander, Jacques Mathurin Lafosse, and 22 dragoons escaped the debacle. Emboldened by his victory, Eroles decided to engage a French force six days later at Altafulla and suffered the loss of between 600 and 2,000 men. Uncowed by his defeat, Eroles repulsed Jean Raymond Charles Bourke's French force when it attacked him at Roda de Isábena on 5 March.