The Prisoner of Zenda(1979)

Anthony Hope's classic tale gets a decidedly 'un-classic' treatment at the hands of Peter Sellers. Following the story somewhat, friends of the new King Rudolph of Ruritania fear for his life, and switch him with a look-a-like London cabby. Throw in two(!) lovely blondes, treachery, and a battle for life and honour, and enjoy life at its zaniest.