Catherine was an Italian noblewoman who married King Henri II of France. During her husband's life, she was excluded from participation in state affairs and had to put up with her husband's mistress, Diane de Poitiers, who was omni-present at court.

At Henri's death, Catherine gained influence as the mother of new French king Francis II. Francis died very quickly, and in turn, his very young brother King Charles IX sat on the throne, with his mother as regent. Bad luck plagued the family and after Charles passed away, Henri III, her 3rd son sat on the throne of France.

Catherine is known to have had a great influence in matters of the state at that time, but also in the lives of her own children. Many saw her as a sinister queen, who versed in the occult, consulted astrologers such as Nostradamus, and necromancers.

Catherine's life was during a time of great turmoil in French history. Many situations forced her to have a tight grip over power and the French crown; she was notorious for having participated in atrocities such as the St Bartholomew's Day massacre, during which many protestants were killed throughout France. She was known to be a ruthless queen who went to great length to keep the Valois dynasty on the throne.