Born William Henry Pratt in England,[1] he emigrated to Canada in 1909 as a young man and eventually joined a Canadian touring company, adopting the stage name Boris Karloff.
By 1919, Karloff moved to Hollywood[1] where he found regular work as an extra at Universal Studios.
Although he appeared in numerous silent films, Karloff's first significant roles were in Howard Hawks's The Criminal Code (1931) and Mervyn LeRoy's Five Star Final (1931).
After Frankenstein and starring in several high-profile films such as Bride of Frankenstein (1935)[2] and The Mummy (1932), Karloff spent the remainder of the 1930s working at an incredible pace, but getting progressively involved in lower budget films.
Karloff starred in a few highly acclaimed Val Lewton-produced horror films in the 1940s, and by the mid-1950s, he was a familiar presence on both television and radio, hosting his own TV series including Starring Boris Karloff, Colonel March of Scotland Yard, Thriller, Out of This World (British TV series) and The Veil, and guest starring on such programs as Suspense, The Donald O'Connor Show, I Spy and Route 66.