Born in 1343 - died in Paris, 1377.
Military leader, son of Jean II de Grailly and Blanche de Foix. Celebrated by Froissart as a paragon of chivalrous virtue. Like his ancestors, he ardently embraced the English quarrel against the House of France, so much so that Edward III entrusted him with the county of Bigorre and conferred on him the Order of the Garter. Lieutenant of the Black Prince, he shares with Chandos the laurels of the Battle of Poitiers (1356). The following year, he went to war in Prussia with his cousin Gaston Phébus. In 1364, du Guesclin defeated him at Cocherel. After making him promise to abandon the English cause, Charles V frees him and, to win him over, gives him the lordship of Nemours. But the captal is not long in returning to the party which made the fortune of his ancestors. This attitude earned him the appointment in 1371, by Edward III, constable of Aquitaine. In 1372, near Soubise, he again fell into the hands of the French who, this time, kept him in prison, in the Temple of Paris, where he died.