At the tender age of 14, orphan Catherine de' Medici marries King Henry II as part of a geopolitical alliance masterminded by her uncle, Pope Clement. Thrust into a world of shifting fortunes, young Catherine discovers that her spouse is madly in love with lady-in-waiting Diane de Poitiers, a woman twice his age. Catherine adapts quickly to secure her place as one of the most powerful and longest-serving rulers in French history.