Kurš apprecējās ar Isabella of Navarre, Countess of Armagnac?

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.

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.