Rainier III, Prince of Monaco Rainier III, Prince of Monaco Rainier III (Rainier Louis Henri Maxence Bertrand Grimaldi; 31 May 1923 – 6 April 2005) ruled the Principality of Monaco for almost 56 years, making him one of the longest ruling monarchs in European history. Though internationally known for his marriage to American actress Grace Kelly, he was also responsible for reforms to Monaco's constitution and for expanding the principality's economy beyond its traditional casino gambling base. Gambling accounts for only approximately three percent of the nation's annual revenue today; when Rainier ascended the throne in 1949, it accounted for more than 95 percent. Rainier
Honoré IV, Prince of Monaco Honoré IV, Prince of Monaco Honoré IV (17 May 1758 – 16 February 1819) was Prince of Monaco and Duke of Valentinois from 12 March 1795 to 16 February 1819. He was the son of Prince Honoré III by his wife, Maria Caterina Brignole, a Genoese noblewoman. After the fall of Napoleon I, he regained control of the principality thanks to a clause added by Charles Maurice de Talleyrand-Périgord at the Congress of Vienna stating that, " "the Prince of Monaco should return to his estates"", and passed on his titles to his eldest son, Honoré V, Prince of Monaco.