The long-reigning king of Hollywood horror, Boris Karloff was born William Henry Pratt on November 23, 1887, in South London. The youngest of nine children, he was educated at London University in preparation for a career as a diplomat. However, in 1909, he emigrated to Canada to accept a job on a farm, and while living in Ontario he began pursuing acting, joining a touring company and adopting the stage name Boris Karloff. His first role was as an elderly man in a production of Molnar's The Devil, and for the next decade Karloff toiled in obscurity, traveling across North America in a variety of theatrical troupes. By 1919, he was living in Los Angeles, unemployed and considering a move into vaudeville, when instead he found regular work as an extra at Universal Studios. Karloff's first role of note was in 1919's His Majesty the American, and his first sizable part came in The Deadlier Sex a year later. Still, while he worked prolifically, his tenure in the silents was undistinguished, although it allowed him to hone his skills as a consummate screen villain.
Karloff's first sound-era role was in the 1929 melodrama The Unholy Night, but he continued to languish without any kind of notice, remaining so anonymous even within the film industry itself that Picturegoer magazine credited 1931's The Criminal Code as his first film performance. The picture, a Columbia production, became his first significant hit, and soon Karloff was an in-demand character actor in projects ranging from the Wheeler and Woolsey comedy Cracked Nuts to the Edward G. Robinson vehicle Five Star Final to the serial adventure King of the Wild. Meanwhile, at Universal Studios, plans were underway to adapt the Mary Shelley classic Frankenstein in the wake of the studio's massive Bela Lugosi hit Dracula. Lugosi, however, rejected the role of the monster, opting instead to attach his name to a project titled Quasimodo which ultimately went unproduced. Karloff, on the Universal lot shooting 1931's Graft, was soon tapped by director James Whale to replace Lugosi as Dr. Frankenstein's monstrous creation, and with the aid of the studio's makeup and effects unit, he entered into his definitive role, becoming an overnight superstar.
Touted as the natural successor to Lon Chaney, Karloff was signed by Universal to a seven-year contract, but first he needed to fulfill his prior commitments and exited to appear in films including the Howard Hawks classic Scarface and Business or Pleasure. Upon returning to the Universal stable, he portrayed himself in 1932's The Cohens and Kellys in Hollywood before starring as a nightclub owner in Night World. However, Karloff soon reverted to type, starring in the title role in 1932's The Mummy, followed by a turn as a deaf-mute killer in Whale's superb The Old Dark House. On loan to MGM, he essayed the titular evildoer in The Mask of Fu Manchu, but on his return to Universal he demanded a bigger salary, at which point the studio dropped him. Karloff then journeyed back to Britain, where he starred in 1933's The Ghoul, before coming back to Hollywood to appear in John Ford's 1934 effort The Lost Patrol. After making amends with Universal, he co-starred with Lugosi in The Black Cat, the first of several pairings for the two actors, and in 1936 he starred in the stellar sequel The Bride of Frankenstein.
Karloff spent the remainder of the 1930s continuing to work at an incredible pace, but the quality of his films, the vast majority of them B-list productions, began to taper off dramatically. Finally, in 1941, he began a three-year theatrical run in Arsenic and Old Lace before returning to Hollywood to star in the A-list production The Climax. Again, however, Karloff soon found himself consigned to Poverty Row efforts, such as 1945's The House of Frankenstein. He also found himself at RKO under Val Lewton's legendary horror unit. A few of his films were more distinguished -- he appeared in The Secret Life of Walter Mitty, Unconquered, and even Abbott and Costello Meet the Killer -- and in 1948 starred on Broadway in J.B. Priestley's The Linden Tree, but by and large Karloff delivered strong performances in weak projects. By the mid-'50s, he was a familiar presence on television, and from 1956 to 1958, hosted his own series. By the following decade, he was a fixture at Roger Corman's American International Pictures. In 1969, Karloff appeared in Peter Bogdanovich's Targets, a smart, sensitive tale in which he portrayed an aging horror film star; the role proved a perfect epitaph -- he died on February 2, 1969.