Rainier III, Prince of Monaco of Monaco, the Palais Princier announced that Rainier's son, Hereditary Prince Albert, would take over the duties of his father as regent since Rainier was no longer able to exercise his royal functions. On 1 April 2005, the Palace announced that Rainier's doctors believe his chances of recovery were "slim". On 6 April, Prince Rainier died at the Cardiothoracic Center of Monaco at 6:35 AM local time at the age of 81. He was succeeded by his only son, who became Prince Albert II. He was buried on 15 April 2005, beside his wife, Princess Grace, at the Cathedral of
Honoré IV, Prince of Monaco Honoré IV, Prince of Monaco Honoré IV (17 May 1758 – 16 February 1819) was Prince of Monaco and Duke of Valentinois from 12 March 1795 to 16 February 1819. He was the son of Prince Honoré III by his wife, Maria Caterina Brignole, a Genoese noblewoman. After the fall of Napoleon I, he regained control of the principality thanks to a clause added by Charles Maurice de Talleyrand-Périgord at the Congress of Vienna stating that, " "the Prince of Monaco should return to his estates"", and passed on his titles to his eldest son, Honoré V, Prince of Monaco.