Blatty wrote several books but his signature achievement was the 1971 novel that told the story of a 12-year-old girl whose vile behavior leads a young priest to conclude that she is possessed by a demon.
The novel was panned by critics but went on to sell 13 million copies, topping The New York Times bestseller list for 17 weeks, and is retrospectively considered to be one of the greatest horror novels of all time.
Blatty won an Oscar for his screenplay of his own book for the 1973 film and later wrote and directed a sequel, 1990’s “The Exorcist III.”
The original film, directed by William Friedkin and starring Linda Blair, was a box-office hit and cult sensation that sparked a worldwide debate about the occult within the Catholic Church and inspired a generation of horror filmmakers.
Blatty, raised a devout Roman Catholic, died at a hospital near his home in Bethesda, Maryland, on Thursday, but it was announced on social media by Friedkin on Friday.