The Battle of Castellón was an ambush delivered against a French Imperial detachment under General Reille near Girona. Having crept his force up along the right bank of the Fluvià and set up headquarters at La Armentera, a village near the river's mouth on the Mediterranean Sea, General Lazán prepared a coup de main against the French battalion installed atop Castelló d'Empúries. Since bad roads precluded a night attack, Lazán moved in the early morning, brusquely forcing the French off the ridge. While Reille's troops effected a disciplined fighting withdrawal toward Rosas, the Chasseurs de Clarós, acting as the vanguard for General Castro's division, circled across their path of retreat and set up a position in a grove next to the main road, preparing to block the French passage. Caught