The son of a wealthy merchant, Mason decided he could make more money on the stage than designing buildings, and played with the Old Vic and the Gate Company in Dublin. He first appeared onscreen in British "quota quickies" and caused a sensation as a handsome, sadistic aristocrat in the 1943 costume drama, "The Man in Grey".

After another triumphant appearance in Carol Reed's Irish suspense thriller, "Odd Man Out" (1947), the brooding, gifted Mason became Britain's biggest star, moving to Hollywood soon after. Although Southern California softened his rougher edges, he soon reaffirmed his