Taissa Farmiga, who played Sister Irene in this film, is the younger sister of Vera Farmiga in real life, who played Lorraine Warren in The Conjuring (2013) and The Conjuring 2 (2016). The Demon Nun, played by Bonnie Aarons, also appeared in The Conjuring 2 (2016). Though the sister's characters are not at all related to each other, they are both devout Catholics with clairvoyant abilities.
After the "Demon Nun" from The Conjuring 2 (2016) proved to be a popular horror antagonist, a spin-off focusing on the character was green-lit, making her the second character from the franchise to get her own feature after Annabelle (2014).
The events take place before Annabelle: Creation (2017), making it the first movie (chronologically) in the film series.
This was Valak's third appearance after The Conjuring 2 (2016) and Annabelle: Creation (2017).
An advertisement for the film was pulled from the video sharing site YouTube, as many users complained that the five second clip featuring a startling jumpscare was "too scary." Administrators thus removed the ad and apologized, claiming that it was not their intention to publish content that may potentially "offend" or "shock" viewers.
The name of the nun "Valak" can be seen on the playground where we first meet sister Irene on the playground equipment
Despite the Conjuring and its sequel being based on true events, this film is not based on any real historical events and is entirely fictional
The real name of the Nun - Valak - can be seen on the registration plate on the local villager's vehicle just before Father Burke, Sister Irene and Frenchie depart for the abbey.
Filming took place at the Corvin Castle in Hunedoara and in Sighisoara, Transylvania.
The film was originally set to hit cinemas in mid-July of 2018 but was pushed back closer to Halloween season on September 7, in hopes of doing as successful at the box office as It (2017) did last year, which smashed records and earned more than USD $700M.
Writer David Leslie Johnson-McGoldrick was replaced by Gary Dauberman and James Wan.
Director Corin Hardy revealed that reshoots of the film were carried out by both him and James Wan. While Hardy reshot interiors, Wan was reshooting exteriors.
Principal photography for the film began on May 3, 2017 at Castel Film Studios in Bucharest, Romania, with Maxime Alexandre serving as cinematographer. Scenes were filmed in the Palace of the Parliament building in June, for a fee of EUR5,000 per hour.
The first movie in The Conjuring universe not to feature Joseph Bishara, either as an actor or composer.
Many of the nuns describe feeling the presence of spirits, the seeing of visions, and divination. This actually would never happen because according to traditional Roman Catholic religion, these things do not appear to prayerful individuals such as clergy
Every background for "church scenes" had to be done from scrap as it is banned in Romania to film actual churches.