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
Rainier III, Prince of Monaco have been romantically involved with his second cousin, Princess Ira von Fürstenberg, a former actress turned jewellery designer, who is also a Fiat heiress and the former sister-in-law of fashion designer Diane von Fürstenberg. Princess Ira, like him, is a great-grandchild of Lady Mary Victoria Hamilton, the Scottish-German wife of Prince Albert I of Monaco, though by Lady Mary's second marriage. After Grace's death, Rainier refused to remarry. Rainier established a postal museum in 1950: the Museum of Stamps and Coins, in Monaco's Fontvieille district by using the collections of the Monegasque princes Albert I and Louis II. The prestigious