William Peter Blatty was an American writer and director. Blatty is best known for his 1971 horror novel The Exorcist and its screenplay adaptation, which won an Oscar for Best Adapted Screenplay. The film was also nominated for Best Picture.

Born and raised in New York City, Blatty received his bachelor’s degree in English from Georgetown University in 1950, and in 1954 a master’s in English literature from the George Washington University. After his higher education, Blatty joined the United States Air Force and served in the Psychological Warfare Division, then soon after worked for the United States Information Agency in Beirut.

In 1978, after the success of The Exorcist, Blatty revised his own 1966 novel “Twinkle, Twinkle, Killer Kane” into a new book titled The Ninth Configuration. He went on to adapt the novel into a film version in 1980, which was also his directorial debut. The Ninth Configuration won Best Screenplay and was nominated for Best Picture at the 38th Annual Golden Globe Awards.

After refusing to be involved with the first sequel to The Exorcist, Blatty directed the third adaption, The Exorcist III in 1990, which he also scripted, based on his 1983 novel Legion. The film would be Blatty’s final screenplay credit. Some of his more popular later novels include Elsewhere (2009), Dimiter (2010) and Crazy (2010).