Charles IX died in 1574 and the Duke of Anjou inherited the French throne as Henry III. Between 1578 and 1581 the Queen resurrected attempts to negotiate a marriage with Henry III's youngest brother, the Duke of Alençon, who had put himself forward as a protector of the Huguenots and a potential leader of the Dutch. Walsingham was sent to France in mid-1581 to discuss an Anglo-French alliance, but the French wanted the marriage agreed first and Walsingham was under instruction to obtain a treaty before committing to the marriage. He returned to England without an agreement. Personally, Walsingham opposed the marriage, perhaps to the point of encouraging public opposition. Alençon was a Catholic and as his elder brother, Henry III, was childless, he was heir presumptive to the French throne. Elizabeth was past the age of childbearing and had no clear successor. If she died while married to him, her realms could fall under French control. By comparing the match of Elizabeth and Alençon with the match of the Protestant Henry of Navarre and the Catholic Margaret of Valois, which occurred in the week before the St. Bartholomew's Day massacre, the "most horrible spectacle" he had ever witnessed, Walsingham raised the spectre of religious riots in England in the event of the marriage proceeding. Elizabeth put up with his blunt, often unwelcome, advice, and acknowledged his strong beliefs in a letter, in which she called him "her Moor [who] cannot change his colour".