Daughter of Lorenzo de' Medici, wife of Henry II. of France, and mother of his three successors; on the accession of her second son, Charles IX.—for the reign of her first, Francis II., was very brief—acted as regent during his minority; joined heart and soul with the Catholics in persecuting the Huguenots, and persuaded her son to issue the order which resulted in the massacre of St. Bartholomew; on his death, which occurred soon after, she acted as regent during the minority of her third son, Henry III., and lived to see both herself and him detested by the whole French people, and this although she was during her ascendency the patroness of the arts and of literature (1519-1589).