This movie was made and released about eighty-five years after Anthony Hope's novel "The Prisoner of Zenda" was first published in 1894.
Lead actors Peter Sellers and Lynne Frederick were married at the time that this movie was made and released. This picture is the only film they made together as actors. Frederick though does have an executive producer credit on Sellers' final film Le Complot diabolique du Dr. Fu Manchu (1980).
Peter Sellers was the eighth actor to play The Prisoner of Zenda (aka King Rudolph V of Ruritania) in film and television.
The first of a three picture deal that Peter Sellers signed with the Mirisch Company. The other two were never made.