Caroline, Princess of Hanover Caroline, Princess of Hanover Caroline, Princess of Hanover (Caroline Louise Marguerite Grimaldi; born 23 January 1957), is the eldest child of Rainier III, Prince of Monaco, and the American actress Grace Kelly. She is the elder sister of Prince Albert II and Princess Stéphanie. Until the births of her niece and nephew, Princess Gabriella and Prince Jacques, in December 2014 she had been heir presumptive to the throne of Monaco since 2005, a position which she previously held from 1957 to 1958. Caroline is married to Ernst August, Prince of Hanover (born 1954), the heir to the former throne of
Honoré III, Prince of Monaco of Maria Clementina Sobieski. The marriage never materialised and as such, in 1751, he married Maria Caterina Brignole (d. 1813). The couple had two children; Honoré IV, Prince of Monaco and Joseph Grimaldi (10 September 1763 – 28 June 1816) before divorcing in 1770, and Marie-Catherine married the Prince de Condé in 1798. Honoré III, Prince of Monaco Prince Honoré III, Prince of Monaco (10 November 1720 – 21 March 1795) ruled as Prince of Monaco and was Duke of Valentinois from 1731 to 1793. Honoré was the son of Louise Hippolyte, Princess of Monaco and her husband Prince Jacques.