After nine years of inconclusive but expensive warfare, Edward landed with an army in northern Normandy in July 1346. He then undertook a large-scale raid through Normandy, including the capture and sack of Caen, to the gates of Paris. After retreating in the face of Philip's large and increasing army, the English turned to fight at the Battle of Crécy, where the French were defeated with heavy loss. Edward needed a defensible port where his army could regroup and be resupplied from the sea. The Channel port of Calais suited this purpose. It was also highly defensible: it boasted a double moat; substantial city walls; and its citadel in the north-west corner had its own moat and additional fortifications. It would provide a secure entrepôt into France for English armies. Calais could be easily resupplied by sea and defended by land.