Prince Louis II, Prince Rainier's grandfather, became the sovereign leader of Monaco in 1922. In 1944, Princess
Charlotte wrote to her father, Prince Louis II, renouncing her rights to the throne in favor of her son, Prince Rainier. In May 1949, after several months of ill health, Louis II relinquished the throne to Prince Rainier, who on 5 May became the thirty-first hereditary ruler of Monaco. Prince Louis II died a week later.