In spite of her now brilliant prospects, Catherine's position at court was unchanged by the Dauphin's death; her childlessness made a divorce seem probable when her husband should become king. The Dauphin was now enslaved by Diane de Poitiers, who had dared to be the rival of Madame d'Etampes. Catherine was therefore doubly attentive and insinuating to her father-in-law, understanding that he was her sole mainstay. Thus the first ten years of Catherine's married life were spent in the unceasing regrets caused by repeated disappointments when she hoped to have a child, and the vexations of her rivalry with Diane. Imagine what the life must be of a princess constantly spied on by a jealous mistress who was favored by the Catholic party, and by the strong support the Sénéchale had acquired through the marriage of her daughters--one to Robert de la Mark, Duc de Bouillon, Prince de Sédan; the other to Claude de Lorraine, Duc d'Aumale. Swamped between the party of the Duchesse d'Etampes and that of the Sénéchale (the title borne by Diane de Poitiers during the reign of Francis I.), who divided the Court and political feeling between the two mortal foes, Catherine tried to be the friend of both the Duchess and Diane de Poitiers. She, who was to become so great a queen, played the part of a subaltern. Thus she served her apprenticeship to the double-faced policy which afterwards was the secret clue to her life. At a later date the queen found herself between the Catholics and the Calvinists, as the woman had been, for ten years, between Madame d'Etampes and Madame de Poitiers. She studied the contradictions of French policy. Francis upheld Calvin and the Lutherans, to annoy Charles V. Then, after having covertly and patiently fostered the Reformation in Germany, after tolerating Calvin's presence at the Court of Navarre, he turned against it with undisguised severity. So Catherine could see the Court and the women of the Court playing with the fire of heresy; Diane at the head of the Catholic party with the Guises, only because the Duchesse d'Etampes was on the side of Calvin and the Protestants.