On screen
Cast
17 credited performers
Peter Sellers
Rudolf IV/Rudolf V/Sidney Frewin
Stuart Wilson
Rupert
Lynne Frederick
Princess Flavia
Elke Sommer
Countess Montparnasse
Gregory Sierra
Count Montparnasse
Catherine Schell
Mauban
Jeremy Kemp
Duke Michael
John Laurie
Archbishop
Ian Abercrombie
Johann
Simon Williams
Character not listed
Lionel Jeffries
Colonel Zapt
Michael Balfour
Character not listed
Graham Stark
Character not listed
Michael Segal
Character not listed
Arthur Howard
Character not listed
Norman Rossington
Character not listed
Brendan Dillon
Joseph (uncredited)