Four months after the wedding, on 15 December 1415, John's elder brother Louis, Dauphin of France, died; and thus John became the heir to the throne, with Jacqueline as the Dauphine and future Queen consort. Duke William II, who had raised John since childhood, as the father-in-law of the future King obtained a considerable influence at the French court; however, despite this he was less successful in his efforts with the German King Sigismund of Luxembourg to recognize Jacqueline as his rightful heir in the Counties of Holland, Zeeland and Hainaut. In March 1416, Count William raised the matter with Sigismund while the latter was the guest of the English king, Henry V of England, but was rejected; he angrily returned home.