Monaco succession crisis of 1918 of this event, pursuant to the clauses of the treaty of 17 July 1918." The French government at the time was still the Vichy regime. Louis II died on 9 May 1949. The Principality of Monaco passed to his grandson, Rainier III. In the absence of an heir male, the ducal titles of Valentinois and Estouteville became extinct in French nobiliary law. Before Rainier III married Grace Kelly in April 1956, he notified the French government of his plans; the French ministry of foreign affairs replied with a message of official congratulations. Count Louis de Causans is suing the French
Princess Florestine of Monaco his succession to the princely throne of Monaco and the Grimaldi noble titles. However, France had undergone two wars against Germany and did not wish to see German princes ruling the Principality of Monaco. Therefore, France reached an agreement with the principality allowing the illegitimate daughter of Louis II, Charlotte, to be his heir presumptive to the princely throne and Grimaldi noble titles. Charlotte renounced and ceded her rights to the princely throne on 30 May 1944 to her son Rainier who became Rainier III, Prince of Monaco. Princess Florestine of Monaco Princess "Florestine" Gabrielle Antoinette of Monaco (Full French