Reinhold Schünzel Director Nelson Eddy Prince Peter Karagin Actor Ilona Massey Lydia Pavlovna Marakova Actor Charlie Ruggles Nicki Popoff Actor Frank Morgan Ivan Danchenoff Actor Lionel Atwill Prof. Marakov Actor C. Aubrey Smith Gen. Karagin Actor Joyce Compton Masha Actor Dalies Frantz Dimitri Marakov Actor Walter Woolf King Capt. Michael Sibirsky Actor Phillip Terry Lt. Smirnoff Actor Frederick Worlock Ramensky Actor Abner Biberman Leo Proplinski Actor Arthur W. Cernitz Capt. Sergei Pavloff Actor Roland Varno Lt. Nikitin Actor George Tobias Slaski Actor Paul Sutton Anton Actor Willy Castello Capt. Testoff Actor Paul Irving Prince Morodin Actor Mildred Shay Jeanette Sibirsky Actor Alma Kruger Mrs. Danchenoff Actor Zeffie Tilbury Princess Natalya Petrovna Actor Leon Gordon Screenwriter Charles Bennett Screenwriter Jacques Deval Screenwriter Lawrence Weingarten Producer Karl Freund Cinematographer Joseph Ruttenberg Cinematographer George Boemler Film Editing Herbert Stothart Original Music Cedric Gibbons Art Director Edwin B. Willis Set Decoration Adrian Costume Design Valles Costume Design