The Exorcist is an American horror media franchise that originated with William Peter Blatty's 1971 horror novel and most prominently featured in a 1973 film adaptation of the novel, spawned many subsequent prequels and sequels although none of them compared positively to the original. All of these installments focus on fictional accounts of people possessed by Pazuzu, the main antagonist of the series, and the efforts of religious authorities to counter this possession.