He took the side of the English during the Hundred Years" War, and carried out a number of chevauchées on behalf of the Regent Bedford. In 1425, he seized the seigneurie of Guise, which he had disputed with René of Anjou. He joined Philip III, Duke of Burgundy in the Siege of Compiègne in 1430.
While the siege was ultimately unsuccessful, a soldier in his company (the Bastard of Vendôme) captured Joan of Arc, whom he sent to Beauvoir as a prisoner.
Shortly thereafter, his great-aunt Jeanne of Luxembourg, who was then living with him, died and left him the County of Ligny. Under pressure from England and Burgundy, John ultimately sold Joan to the English for 10,000 livres, thus causing her death.