“The Serpent Queen” tells the story of Catherine de Medici (Samantha Morton) who, against all odds, became one of the most powerful and longest-serving rulers in French history.Catherine’s tale unfolds through flashbacks as she defends her actions and imparts the lessons she’s learned to her new servant girl, Rahima (Sennia Nanua). At 14, the young, orphaned Catherine (Liv Hill) marries into the 16th-century French court. Despite her commoner status, her uncle Pope Clement (Charles Dance), has negotiated a large dowry and a geopolitical alliance in return for the union, and with it comes the expectation of many heirs. However, on her wedding night, Catherine learns that her new husband is in love with Diane de Poitiers (Ludivine Sagnier), a beautiful lady-in-waiting twice his age. With her future suddenly uncertain and with little hope of conceiving, Catherine must quickly learn who she can trust -both within her personal entourage of courtiers and the members of the royal court -while outmaneuvering anyone who underestimates her determination to survive at any cost.