Lockwood
Leuwen Grayle
Gordon Moore
Gordon Druce
Professor Langer
Lord Wickham
Giles Conover
Judge Brisson
Portmaster
King Henry VI
Deacon Arnold Foster
Wriothesley
Lord Keith
Aramis
Levett
Dr. Kurt Immelman
Homer
Tom Armitage
Jukes
Dr. Lockberg
Doctor (uncredited)
British Secretary
Dr. Marko
Sir Hugo Boycott
Chief Inspector W.R. Allison
Cardinal Richelieu
Hon Gerald Pillick
Kilpatrick
German Agent on Radio (voice) (uncredited)
Dr. Wilton
Garry Ames
Corey
Charles Seagrave
Dr. Rankin
Mr. Rogan
Col. Herman Fournier
Horace Granville
Capt. Ronald Dancy, DSO
James Stratton
The Sparkler
Benjamin Disraeli
Adolf Sperber
Armand de Marny
Floyd Kirsten
Rollo Stevens
Mr. Charles Pryor
Sir Frederick Fleet
Sir John Gresham
James V. Thorne
Roger Smythe
Ebenezer Balfour
Feize
Harley Travers
Raymond Carteret
Guy Merrow
Attorney General (uncredited)
Lieut. Strope
Colonel Fitzhume (uncredited)
Dr. Leonard V. Meecham
Frederick Malone
Paul Panois
Captain Auguste Lutte
Capt. Gardner
King Louis XIII
Bert
Mr. Brigstock
Sir Malcolm Drake (uncredited)
Sir Neville Moreton
Pleyel
Claude Holford
Major Loring (uncredited)
Harry Tresham
Ambatriadi
Over the Shoulder Reader
Major Cunningham
Sir Robert Bentley
Fred Thomas
Businessman (uncredited)
Major
Lord Warrick
Weatherby (uncredited)