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
Monaco villas to poor documentation and archiving. As of 2016, Monaco still had no official preservation laws governing historic buildings. In 1960 Prince Rainier III established the Monaco Economic Development Corporation to attract new business to the Principality. It was successful in this, but the influx of new investors and workers resulted in a wave of demolitions of Belle Epoque villas to enable the construction of apartments and new hotels. Following major development in the 1970s, Prince Rainier III banned high rise development in the Principality. However his successor, Prince Albert II, overturned the Sovereign Order. This, and a further influx of