No Palácio Real de Ruritânia, o rei morre e deixa dois filhos, um bom, Príncipe Rodolf, e um ruim, Príncipe Michael; o desejo do pai era que o trono ficasse com o Príncipe Rodolf, mas o malvado do Príncipe Michael prepara algumas surpresas...
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.
A kingdom's ascending heir, marked for assassination, switches identities with a lookalike, who takes his place at the coronation. When the real king is kidnapped, his followers try to find him, while the stand-in falls in love with the king's intended bride, the beautiful Princess Flavia.