Today marks the 15th Anniversary of the Death of Prince Rainier III of Monaco, who died on this day in 2005. The only son of Princess Charlotte, Duchess of Valentinois, the illegitimate but adopted daughter of Prince Louis II of Monaco, and Count Pierre de Polignac, he was the first Monegasque Prince born in Monaco since 1858. Prince Rainier was educated at Summerfields in St Leonards-on-Sea, Sussex, and later at Stowe, in Buckinghamshire in England, before attending the Institut Le Rosey in Rolle and Gstaad, Switzerland, before going to the University of Montpellier in France, and then the Institut d’études Politiques de Paris. In 1944, upon his 21st birthday, Princess Charlotte renounced her right to the Monegasque Throne and Prince Rainier became his grandfather’s direct heir, becoming the Sovereign Prince of Monaco in 1949. During World War II, Prince Rainier joined the Free French Army, receiving the French Croix de Guerre and then given the rank of Chevalier in the French Legion of Honor in 1947. In 1956, Prince Rainier married American Actress Grace Kelly, and the couple had three children: Prince Albert, Princess Caroline, and Princess Stephanie, remaining happily married until her untimely death in 1982. Prince Rainier’s long reign saw a complete transformation in the reputation and financial circumstances of the Principality, and he was the world’s 2nd longest reigning Head of State at the time of his death on this day in 2005.