The English army in the north, after its victory at Crécy, went on to besiege Calais. Lancaster joined it there in the summer of 1347 and was present when Calais fell after an eleven-month siege, securing an English entrepôt into northern France which was held for two hundred years. The war in southwest France stayed far from Gascony. In 1355 Edward III's eldest son, Edward, the Black Prince, led a large-scale "chevauchée" north from Bordeaux that devastated France. After another devastating "chevauchée" in 1356, the French army, commanded by Duke John, now King John II of France, intercepted it and forced the outnumbered English to battle from Poitiers; the French were decisively defeated and John was captured.