Gaston married Infanta Eleanor of Navarre in 1436.[2] Her parents were John II and Blanche I of Navarre. At the time, Eleanor appeared to have few prospects: her father was a younger son and brother of kings of Aragon, and she had two older siblings, Charles and Blanche, standing between herself and the throne of Navarre. However, family dissent and death eliminated both her siblings; Eleanor's father usurped the Navarrese crown, to which he added in 1458 the throne of Aragon (his older brother having died without legitimate children). Following the deaths of Charles and Blanche, King John promised the succession to Navarre to Eleanor and Gaston in return for their loyalty to him, which was given.
Gaston and Eleanor had:
Gaston de Foix (1443–1470), (sometimes called “Gaston V of Foix”), Viscount of Castelbon, Prince of Viana (1462–1470), lieutenant general of Navarre (1469).[3]
Jean de Foix (1446–1500), Viscount of Narbonne (1468–1500), Count d'Étampes (1478–1500). He claimed the throne of Navarre upon the death of his nephew François Phébus. He married in 1476 Marie of Orleans, sister of the future King of France Louis XII.[4]
Pierre de Foix (7 February 1449 – 10 August 1490), (sometimes called “Pierre II of Foix”), called Pierre the Young, cardinal (1576),[4] viceroy of Navarre (1479–1484)
Jacques de Foix, Infante de Navarra (1469 – in France 1500), Count de Montfort. Married in 1485 and divorced in 1494 Ana de Peralta,[4] daughter of Pedro de Peralta, 1st Count de Santisteban y Lerín and his second wife Isabelle de Grailly. Married secondly in 1495 Catherine de Beaumont,[4] daughter of Louis de Beaumont, 2nd Count de Lerín and his wife Leonor de Aragón. Jacques and his second wife had one child: Jean de Foix, abbot of Saint-Volusien-de-Foix. Jacques also had two illegitimate children by unknown mistresses: Frederic de Foix (d. 1537), Seigneur d'Almenèches, and Jacques de Foix (d. 7 Apr 1535), Bishop of Oloron and Lescar.
More information Ancestors of Gaston IV, Count of Foix ...
Krochalis, Jeanne E. (1996). "1494: Hieronymous Munzer, Compostela, and the Codex Calixtinus". In Dunn, Maryjane; Davidson, Linda Kay (eds.). The Pilgrimage to Compostela in the Middle Ages. Routledge.
Vernier, Richard (2008). Lord of the Pyrenees: Gaston Fébus, Count of Foix (1331-1391). The Boydell Press.
Ward, A.W.; Prothero, G.W.; Leathes, Stanley, eds. (1911). The Cambridge Modern History. Macmillan Company.
Woodacre, Elena (2013). The Queens Regnant of Navarre: Succession, Politics, and Partnership, 1274-1512. Palgrave Macmillan.