In 1348, the Black Death began to ravage Europe. In 1356, after it had passed and England was able to recover financially, Edward's son and namesake, the Prince of Wales, known as the Black Prince, invaded France from Gascony, winning a great victory in the Battle of Poitiers, where the English archers repeated the tactics used at Crécy. The new French king, John II, was captured. John signed a truce with Edward, and in his absence, much of the government began to collapse. Later that year, the Second Treaty of London was signed, by which England gained possession of Aquitaine and John was freed.
The French countryside at this point began to fall into complete chaos. Brigandage, the actions of the professional soldiery when fighting was at low ebb, was rampant. In 1358, the peasants rose in rebellion in what was called the Jacquerie. Edward invaded France, for the third and last time, hoping to capitalise on the discontent and seize the throne, but although no French army stood against him in the field, he was unable to take Paris or Rheims from the Dauphin, later King Charles V. He negotiated the Treaty of Brétigny which was signed in 1360. The English came out of this phase of the war with half of Brittany, Aquitaine (about a quarter of France), Calais, Ponthieu, and about half of France's vassal states as their allies, representing the clear advantage of a united England against a generally disunified France.
When John's son Louis I, Duc d'Anjou, sent to the English as a hostage on John's behalf, escaped in 1362, John II chivalrously gave himself up and returned to captivity in England. He died in honourable captivity in 1364 and Charles V succeeded him as king of France.