House of Valois the senior descendant of Philip IV of France. Charles' character eventually alienated both the French and English monarchs, because he readily switched sides whenever it suited his interest. In 1356, Edward, the Black Prince, eldest son and heir of Edward III, led an army to a chevauchée in France. John pursued the Black Prince, who tried to avoid battling the French king's superior force. Negotiations broke down. In the Battle of Poitiers, the French suffered another humiliating defeat, and their king was captured. Edward hoped to capitalize on the victory by invading France and having himself crowned at Reims. But
Edward the Black Prince he was taking into his pay. While his army was assembling he remained at Angoulême, and was there visited by Peter. He then stayed over Christmas at Bordeaux, for his wife, Joan, was there brought to bed of her second son Richard (the next king of England). The Black Prince left Bordeaux early in February 1367, and joined his army at Dax, where he remained three days, and received a reinforcement of four hundred men-at-arms and four hundred archers sent out by his father under his brother John, duke of Lancaster. From Dax the prince advanced via Saint-Jean-Pied-de-Port through Roncesvalles