Rainier III, Prince of Monaco
Apart from Onassis's mistress Maria Callas and his wife Jackie Kennedy Onassis, he entertained celebrities such as Umberto Agnelli, Giovanni Battista Meneghini, Richard Burton, Clementine Churchill, Diana Churchill, Winston Churchill, Jacqueline de Ribes, John F. Kennedy, Greta Garbo, Rainier III, Prince of Monaco, Grace Kelly, Anthony Montague Browne, Rudolf Nureyev, Begum Om Habibeh Aga Khan, J. Paul Getty, Eva Perón, Françoise Sagan, Frank Sinatra, Elizabeth Taylor, John Wayne.