Vem gifte sig med John IV, Count of Armagnac?

John IV (15 October 1396 – 5 November 1450) was a Count of Armagnac, Fézensac, and Rodez from 1418 to 1450. He was involved in the intrigues related to the Hundred Years' War and in conflicts against the King of France.

Isabella of Navarre (1395 – 31 August 1450) was the younger surviving daughter of Charles III of Navarre and his wife Eleanor of Castile. She was a member of the House of Évreux.