 However, the senior member of the family, Henry III of Navarre (son of Charles's late elder brother Antoine), was a Protestant.The Catholic League, party to the French Wars of Religion, excluded all Protestants from the succession, which made Charles de Bourbon their champion.In the secret Treaty of Joinville of 31 December 1584 he was recognized by the leaders of the league and a representative of Philip II of Spain as the heir to Henry III of France.