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
Albert II, Prince of Monaco since Rainier was no longer able to exercise his royal functions. On 6 April 2005, Rainier III died and Albert succeeded him as Albert II. The first part of Prince Albert II's enthronement as ruler of the Principality was on 12 July 2005, after the end of the three-month mourning period for his father. A morning Mass at Saint Nicholas Cathedral presided over by the Archbishop of Monaco, the Most Reverend Bernard Barsi, formally marked the beginning of his reign. Afterward Albert II returned to the princely palace to host a garden party for 7,000 Monégasques born in the principality.