Peter, cardinal of Foix (1386–1464), was the fifth son of Archambault of Grailly, and was made archbishop of Arles in 1450. He took a prominent part in the struggle between the rival popes, and founded and endowed the Collège de Foix at Toulouse. The next count was John's son, Gaston IV of Foix, who married Leonora (died 1479), a daughter of John, king of Aragon and Navarre. In 1447 he bought the viscounty of Narbonne, and having assisted King Charles VII in Guyenne, he was made a peer of France in 1458. In 1455 his father-in-law designated him as his successor in Navarre, and Louis XI of France gave him the counties of Roussillon and Cerdagne, and made him his representative in Languedoc and Guyenne; but these marks of favor did not prevent him from joining a league against Louis in 1471.