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
Monaco succession crisis of 1918 government for US$401 million alleging that France used a "sleight of hand" to deprive Duke Wilhelm II, his ancestor, of the Monacan throne when it passed the 1911 law permitting Charlotte to be considered a Grimaldi. Joseph Valynseele "Rainier III: est-il le souverain legitime de Monaco?" Recueil de l'Office Genealogique et Heraldique de Belgique, XIII (1964), pp. 191–223. Monaco succession crisis of 1918 The Monaco succession crisis of 1918 arose because France objected to the prospect of a German national inheriting the throne of the Principality of Monaco. Prince Albert I had only one legitimate child, the Hereditary Prince Louis,