Within the cinematic realm of “The Conjuring,” a sprawling supernatural universe that draws from the life and career of real-life paranormal investigators Ed and Lorraine Warren, “The Nun” serves as a prequel that delves deeper into its eerie lore. This film, inspired by the Warrens’ documented experiences, is set predominantly in a secluded Romanian abbey during the 1950s. It seeks to unravel the origins of the demonic entity Valak, a central figure in the “Conjuring” saga. The narrative follows Sister Irene, portrayed by Taissa Farmiga (whose sister Vera Farmiga plays Lorraine Warren), as she joins Father Burke (Demián Bichir) to probe a mysterious death within the abbey. As the story unfolds, it reveals that the abbey once belonged to a Dark Ages noble with an obsession with the occult, inadvertently summoning Valak through a breach in the grounds.

While “The Nun” is a fictional tale set before the Warrens’ in-universe encounter with Valak, its concept takes inspiration from their real-life investigation into a haunting near Borley Church and Borley Rectory in Essex, England. These events are chronicled in Gerald Brittle’s biography, “The Demonologist: The Extraordinary Career of Ed and Lorraine Warren.” Ed Warren famously referred to Borley as “the most haunted area in England,” a place he described as a “virtual doorway to the supernatural.” Both he and Lorraine claimed sightings of the Borley nun, with Ed expressing intent to capture her apparition in a photograph during a future visit.

The “Conjuring” universe draws heavily from the real exploits of Lorraine and Ed Warren, portrayed on screen by Patrick Wilson. The Warrens rose to prominence by participating in over a hundred paranormal investigations, sharing their experiences through books, media appearances, and even establishing their own occult museum to house artifacts from their cases.

Many of the stories in the “Conjuring” universe are directly inspired by the real-world versions of “Conjuring” protagonists Lorraine and Ed Warren (Patrick Wilson). During their heyday, the Warrens claimed to have worked on more than 100 paranormal investigations, gaining publicity through books and media interviews as well as founding their own occult museum. 

The world of spooky things has been central to the Warrens’ identity since 1952, when they founded the New England Society for Psychic Research (N.E.S.P.R.). In those early days, the couple would show up at houses that were rumored to be haunted, with Ed using his art skills to create a sketch of each abode as a ruse to get the pair invited inside to investigate. Although she was once skeptical of their ghostly research, Lorraine eventually claimed to be a trance medium, insisting she’d psychically known she would marry Ed from the first day they met at just 16 years old. 

Although wildly fictionalized, several of their real cases feature heavily in “The Conjuring” universe. The Warrens met Annabelle, the allegedly cursed Raggedy Ann doll that inspired the fictional “Annabelle,” in 1970 in a strange set of events culminating in an Episcopalian exorcism. The 1971 Perron family haunting in Rhode Island formed the basis for the first “Conjuring” film, and the Warrens’ alleged encounter with an Enfield, England poltergeist inspired “The Conjuring 2.” “The Conjuring: The Devil Made Me Do It” is based on the true story of “Demon Murder Trial” killer Arne Johnson, a 19-year-old who claimed demonic possession drove him to murder his landlord, Alan Bono, in 1981. The box office hit “The Conjuring: Last Rites” fictionalizes Pennsylvania’s Snurl family haunting. 

“The Conjuring” films might be the most famous films about the Warrens’ experiences, but they’re not the only ones by a longshot. The 1979 film “The Amityville Horror” and the rather long list of related “Amityville Horror” movies was adapted from a book about the Amityville, New York home where, in 1974, Ronald DeFeo shot and killed his mother, father, and four of his five young siblings. Just shy of one month after moving into the DeFeos’ iconic Dutch Colonial home in December 1975, George and Kathy Lutz had moved their family right back out again citing supernatural events related to the DeFeo killings, prompting the Warrens’ investigation. The Warrens would eventually make the unproven, implausible, and culturally insensitive claims that the hauntings were caused in part because an alleged practitioner of black magic named John Ketchum once lived on the grounds and in part because the grounds contained negative energy from a Shinnecock Indian sanitorium. Although the Warrens don’t make an appearance in this film, their experience heavily influenced the story. 

The 2009 supernatural horror movie “The Haunting in Connecticut,” a fever dream about a family with a dying teen as they take up residence in a seriously haunted former funeral parlor, was inspired by an incident with the Warrens and the Snedecker family. Lorraine Warren would claim the real case was far more frightening than any film could impart and involved the sound of coffins scraping across floors and rosary beads pulled apart by a ghostly hand midair. In addition to the Hollywood films, the Warrens’ tales also inspired the 1991 made-for-TV film “The Haunted” based on the Smurl haunting and appeared in a handful of paranormal documentaries including “In Search Of…,” “Scariest Places on Earth,” “Paranormal State,” and “A Haunting.”