He became seigneur (lord of the manor) of Créquy, Canaples and Fressin on the death of his father and was one of the first ‘Knights of the Golden Fleece’, an order started by Philip the Good, Duke of Burgundy. He saw action throughout the Hundred Years War, on either side of the conflict. Jean V was in the service of Philip, Duke of Burgundy(whose allegiances changed twice) and took part in the defence of Paris against Joan of Arc in 1429 and became French ambassador to Aragon.
They had two children: Jacqueline (1457–1509) and Jean (1458–1480).
Jean de Crequy died in 1474.