Princess Antoinette, Baroness of Massy was a member of the princely family of Monaco. She was the elder sister of Prince Rainier III. Her parents were Princess Charlotte, Duchess of Valentinois and her former husband, Count Pierre de Polignac.

The House of Grimaldi is the current reigning house of the Principality of Monaco. The house was founded in 1160 by Grimaldo Canella in Genoa and became the ruling house of Monaco when Francesco Grimaldi captured Monaco in 1297.