Kirk Douglas as Dr. Rolf Pedersen

Richard Harris as Knut Straud

Ulla Jacobsson as Anna Pedersen

Michael Redgrave as Uncle

David Weston as Arne

Anton Diffring as Major Frick

Eric Porter as Terboven

Mervyn Johns as Col. Wilkinson

Jennifer Hilary as Sigrid

Roy Dotrice as Jensen

Barry Jones as Professor Logan

Ralph Michael as Nilssen

Geoffrey Keen as General Bolt

Maurice Denham as Doctor

Wolf Frees as Knippelberg

Robert Ayres as General Courts

Sebastian Breaks as Gunnar

John Golightly as Freddy

Alan Howard as Oli

Patrick Jordan as Henrik

William Marlowe as Claus

Brook Williams as Einar

David Davies as Captain of "Galtesund"

Karl Stepanek as Hartmuller

Faith Brook as Woman on Bus

Elvi Hale as Mrs. Sandersen

Gerard Heinz as Erhardt

Victor Beaumont as German Sergeant

Philo Hauser as Businessman

George Murcell as Sturmfuhrer

Russell Waters as Mr. Sandersen

Jan Conrad as Watchman in Factory

Annette Andre as Girl Student (uncredited)