The English army of some 10,000 men had landed in northern Normandy on 12 July 1346. They embarked on a large-scale raid, or "chevauchée", devastating large parts of northern France. On 26 August 1346, fighting on ground of their own choosing, the English inflicted a heavy defeat on a large French army led by their king Philip VI at the Battle of Crécy. A week later they invested the well-fortified port of Calais, which had a strong garrison under the command of Jean de Vienne. Edward made several unsuccessful attempts to breach the walls or to take the town by assault, either from the land or seaward sides. During the winter and spring the French were able to run in supplies and reinforcements by sea, but in late April the English established a fortification which enabled them to command the entrance to the harbour and cut off the further flow of supplies.