Although this movie was not released until 1962, it was filmed in 1958.
The working title was "Doctor of the Seven Dials", but MGM objected. They thought that foreign audiences would not be familiar with that area of London.
Boris Karloff (Dr. Thomas Bolton) and Sir Christopher Lee (Resurrection Joe) have four roles in common: (1) Karloff played Frankenstein's Monster in Frankenstein (1931), Bride of Frankenstein (1935), and Son of Frankenstein (1939), while Lee played him in The Curse of Frankenstein (1957), (2) Karloff played the Mummy in The Mummy (1932), while Lee played him in The Mummy (1959), (3) Karloff played Dr. Fu Manchu in The Mask of Fu Manchu (1932), while Lee played him in The Face of Fu Manchu (1965), The Brides of Fu Manchu (1966), The Vengeance of Fu Manchu (1967), The Blood of Fu Manchu (1968), and The Castle of Fu Manchu (1969), and (4) Karloff played Grigori Rasputin in The Black Prophet (1953), while Lee played him in Rasputin: The Mad Monk (1966).
This film is part of the Criterion Collection, spine #368.