Fifty-years ago, movie audiences were terrified by the arrival of The Exorcist, directed by William Friedkin and based on the novel by William Peter Blatty. It stars Linda Blair (who was then 12) as Regan MacNeil, whose mother (Ellen Burstyn) brings in a pair of priests (Jason Miller and Max von Sydow) when her daughter shows signs of demonic possession. What follows is a horror tour-de-force as the priests attempt an exorcism against what is a very powerful demon. At the time, this was an unprecedented approach to the horror genre and as frightened and disturbed as the audience was with it, they absolutely loved it. Produced at a cost of $11 million, it pulled it $441 million from around the world. What follows is a behind-the-scenes look at the challenges and other facts about the making of The Exorcist. Inspired by a True Exorcism THE EXORCIST, Linda Blair, 1973. (c) Warner Bros./ Courtesy: Everett Collection. When author William Peter Blatty wrote the novel on which he based his screenplay for the movie adaptation, he was actually inspired by a true exorcism he had read about in a newspaper while he was a student at Georgetown University. RELATED: ‘Exorcist’ Star Linda Blair On If She’s Ever Experienced Paranormal Activity Original Casting Choices For Father Merrin THE GODFATHER, Marlon Brando, 1972 (Everett Collection) Director William Friedkin originally intended to cast Marlon Brando — fresh off of his role as Don Corleone in 1972's The Godfather — in the role of Father Merrin, and also considered Jack Nicholson. In the end, he went with Max von Sydow. Other Actresses Who Could Have Played the Possessed Regan Denise Nickerson WILLY WONKA AND THE CHOCOLATE FACTORY, Denise Nickerson, 1971 (Everett Collection). Best known for playing Amy Jennings on the daytime horror soap opera Dark Shadows and Violet Beauregarde (the girl who becomes a blueberry) in 1971's Willy Wonka and the Chocolate Factory. Donna Pescow ANGIE, Donna Pescow, 1979-89 (1979 photo by Paul Terpanjian). ©ABC/courtesy Everett Collection Fairly unknown at the time, she would eventually star in the television sitcom Angie (1979 to 1980) and played a supporting role in Saturday Night Fever (1977). Pemelyn Ferdin THE PAUL LYNDE SHOW, clockwise from left: Elizabeth Allen, John Calvin, Jane Actman, Pamelyn Ferdin, Paul Lynde, (Septermber 9, 1972), 1972-73. ph: Douglas Jones / TV Guide / ©ABC / Courtesy Everett Collection Very popular child actress who appeared in a wide variety of television series, was a star of The Paul Lynde Show and provided the voice of Lucy in many of the Charlie Brown Peanuts specials in the 1960s. Sissy Spacek BADLANDS, Sissy Spacek, 1973 (Everett Collection) Just a few years before she starred in the 1976 adaptation of Stephen King's Carrie, future Academy Award winner Sissy Spacek auditioned for the role of Regan but was not chosen by director William Friedkin. Director William Friedkin Nearly Turned It Down THE EXORCIST, Director William Friedkin, Ellen Burstyn, 1973. (c) Warner Bros./ Courtesy: Everett Collection. Following the success of 1971's The French Connection, director William Friedkin had his choice of projects and when offered The Exorcist by Warner Brothers, initially turned it down. But then he read the novel and came away from the experience very affected, so ultimately said yes. Production Problems THE EXORCIST, Linda Blair, Barton Heyman, 1973 (Everett Collection) There were a number of problems behind the scenes, including a fire that destroyed the set of Regan's bedroom and a number of injuries suffered by cast and crew. Ellen Burstyn injured her back during a stunt and Linda Blair suffered a spinal injury while filming a scene where she was thrown from her bed. Additionally, several crew members caught pneumonia while shooting the climactic scene in a freezing a freezing attic. Pea Soup Anyone? THE EXORCIST, Linda Blair, 1973. (c) Warner Bros./ Courtesy: Everett Collection. Remember the moment when Regan starts vomiting a green liquid? Well, the famous "pea soup" vomit scene was achieved using a mixture of split pea soup, oatmeal and green food coloring. Sounds as disgusting as it looked! Production Secrets THE EXORCIST, Linda Blair, 1973. (c) Warner Bros./ Courtesy: Everett Collection. The scene where Regan's bed shakes violently was achieved by placing the bed on a platform that was attached to a motor. Also, the director purposely kept the temperature on set very low in order to create a more tense and uncomfortable atmosphere for the actors. And a number of different methods were used to achieve the effect of Regan's head spinning around, including using a fake head and rotating the camera. Some of the effects used in the film were achieved through the use of puppets and animatronics, including the so-called "spider walk" scene. Inspirational THE OMEN, Harvey Stephens, 1976, TM & Copyright (c) 20th Century Fox Film Corp. All rights reserved (Everett Collection). While The Exorcist had been preceded by 1968's Rosemary's Baby (about a woman giving birth to the Devil's child), the success of the film spawned a number of "demonic possession" films, including Abby, The Antichrist and Beyond the Door (all 1974), The Omen (1976), The Manitou (1978) and Poltergeist (1983). And then there was the disastrous Exorcist II: The Heretic (1977), which starred Linda Blair as a 16-year-old Regan but was universally panned, many referring to it as one of the worst films ever made. Voice of the Devil (Everett Collection) Providing the voice of the demon that has possessed Regan — whose name was Pazuzu —was Mercedes McCambridge, winner of the 1949 Academy Award for Best Supporting Actress for the film All the King's Men. She was nominated in the same category for 1956's Giant, starring James Dean. Added to the demon's voice was a combination of Blair's voice, animal noises and various electronic effects.