Boris Karloff, whose real name was William Henry Pratt, was an English-born actor who emigrated to Canada in the 1910s. Karloff performed in a variety of contexts throughout his career, but is best remembered for his roles in horror films and his portrayal of Frankenstein's monster in the 1931 film Frankenstein, 1935 film Bride of Frankenstein, and 1939 film Son of Frankenstein. His popularity following Frankenstein in the early 1930s was such that for a brief time he was billed simply as "Karloff" or, on some movie posters, "Karloff the Uncanny".
Karloff was born at 36 Forest Hill Road, East Dulwich, London, SE22, England, where a blue plaque can now be seen. His parents were Edward John Pratt, Jr. and Eliza Sarah Millard. His paternal grandparents were Edward John Pratt, an Anglo-Indian, and Eliza Julia Pratt, a sister of Anna Leonowens The two sisters were also of Anglo-Indian heritage.
Karloff was brought up in Enfield. He was the youngest of nine children, and following his mother's death was raised by his elder siblings. He later attended Enfield Grammar School before moving to Uppingham School and Merchant Taylors' School, Northwood, and went on to attend King's College London where he studied to go into the consular service. He dropped out in 1909 and worked as a farm labourer and did various odd jobs until he happened into acting. His brother, Sir John Thomas Pratt, became a distinguished British diplomat. Karloff was bow-legged, had a lisp, and stuttered as a young boy. He conquered his stutter, but not his lisp, which was noticeable all through his career.
In 1909, Pratt travelled to Canada and some time later changed his professional name to "Boris Karloff". Some have theorized that he took the stage name from a mad scientist character in the novel The Drums of Jeopardy called "Boris Karlov". However, the novel was not published until 1920, at least eight years after Karloff had been using the name on stage and in silent films. Another possible influence was thought to be a character in the Edgar Rice Burroughs fantasy novel H.R.H. The Rider which features a "Prince Boris of Karlova", but as the novel was not published until 1915, the influence may be backward, that Burroughs saw Karloff in a play and adapted the name for the character. Karloff always claimed he chose the first name "Boris" because it sounded foreign and exotic, and that "Karloff" was a family name. However, his daughter Sara Karloff publicly denied any knowledge of Slavic forebears, "Karloff" or otherwise. One reason for the name change was to prevent embarrassment to his family. Whether or not his brothers actually considered young William the "black sheep of the family" for having become an actor, Karloff himself apparently worried they did feel that way. He did not reunite with his family again until 1933, when he went back to England to make The Ghoul, extremely worried that his siblings would disapprove of his new, macabre claim to world fame. Instead, his elder brothers jostled for position around their "baby" brother and happily posed for publicity photographs with him.