Diane de Poitiers (dyän də pwätyāˈ) [key], 1499–1566, duchess of Valentinois, mistress of King Henry II of France. Noted for her beauty, Diane, who was much older than Henry, retained her influence over him until his death (1559). She maintained friendly relations with the queen, Catherine de' Medici, while completely eclipsing her. In the rivalry for Henry's favor between Anne, duc de Montmorency, and the Guise family, she took sides against whichever party was more powerful at the moment. She supported the king's anti-Protestant policy. After Henry's death, she was forced to retire from the court.
See H. W. Henderson, The Enchantress (1928).
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