The Battle of Ardres was fought in 1351 between French and English forces. The French were victorious. John of Beauchamp had been conducting a raid near Ardres, attacking the neighbourhood of Saint-Omer. However, the French, led by the Lord of Beaujeu, discovered them as they withdrew, and moved to surround them. Beaujeu made all of his men dismount before they attacked, because in the previous Battle of Lunalonge in 1349, the French had lost under similar conditions when they kept many of their men mounted, which had divided their forces too quickly.