For more than 50 years Rainier Grimaldi III ruled the tiny and glamorous principality of Monaco on the south coast of France. Rainier succeeded his grandfather, Prince Louis II, as ruler of Monaco on 9 May 1949. On 18 April 1956 he married American movie star Grace Kelly
, who became known as Princess Grace. The couple had three children: Caroline
(b. 1957), Albert
(b. 1958) and Stephanie
(b. 1965). Though small in size -- its total acreage is smaller than New York's Central Park -- Monaco has long been known for its grand casino, beaches and annual auto race. Rainier was credited with modernizing the principality and building it into a banking center and financial haven for the wealthy. He kept a lower public profile after his wife's 1982 death in an auto accident, and is thought to have been deeply affected by the tragedy. Rainier died in 2005 after struggling with a series of lung infections and other medical problems. After a period of mourning, Rainier's son Albert formally succeeded him on 12 July 2005.