Satan's Slave (released in the United States as Evil Heritage) is a 1976 British supernatural horror film directed by Norman J. Warren.

Its plot follows a young woman who, after surviving a car accident, stays on the country estate of her uncle and cousin, unaware they are both necromancers who intend to sacrifice her to resurrect the spirit of a supernaturally-gifted ancestor.

The film, a production of Warren's newly formed company Monumental Pictures, was funded by producers Les Young and Richard Crafter with their own money and shot almost entirely on location in Pirbright and Shepherd's Bush in December 1975.

[4] According to Steve Green of Flesh and Blood magazine, while the story and "Gothic staging" are reminiscent of "mid-period" Hammer horror films, Satan's Slave sets itself apart by adding an "overt sadistic undercurrent".

[5] Nigel Burrell, also writing for Flesh and Blood, describes the plot as "a stir-fried mix of Dennis Wheatley and Jess Franco, a familiar witchcraft/family curse theme jostling with deranged Black Mass sequences".

[5] Critic Adam Locks notes that Satan's Slave uses plot devices typical of 1970s horror films, including settings that amount to "nowhere places" where characters become lost.

He argues that the effect of the Yorkes' car journey is comparable to time travel, defining it as a "re-programming for the audience with memories and associations disconnected from the modern and the urban [...] In psychogeographical terms of the relationship between the individual and space, there is the clichéd yet interesting idea of the road leading to nowhere."

He describes Alexander as an "atavistic amalgamation of various icons of British gentlemen" – among them the "chivalrous knight", whose moral code he inverts by sacrificing the women in his family.

"[8] After making Her Private Hell (1967) and Loving Feeling (1968), Norman J. Warren had been in negotiations to direct films for Amicus Productions and American International Pictures (AIP).

[14] Although the filmmakers could not afford Michael Gough's usual fee, the actor accepted the role of Alexander after reading McGillivray's script and hearing Warren's personal vision for the film.

Warren remembered the challenges posed by the low budget and how production designer Hayden Pearce found the DeVeuce house: "Most places were not suitable or the people were not interested.

[12][13] These entailed filming a more explicit version of one of the early scenes, in which Stephen nearly rapes, and then brutally murders, a young woman called Janice (played by Gloria Walker) who is staying with him.

[13] Warren considered this version, in which Stephen ties Janice to a bed and threatens to cut off her nipples with scissors, "very unpleasant" and expressed his preference for the original.

[14] Warren also wrote in several additional scenes; one of these, in which Catherine has a vision of a Puritan priest (played by McGillivray) overseeing the torture of a young woman, was filmed in the grounds of a nursing home.

[18] Prior to release, the film's title was changed from Evil Heritage to Satan's Slave as the distributor, Brent Walker, believed that the former was not "commercial" enough.

[1][21][22][23] In a contemporary review for The Monthly Film Bulletin, Michael Grossbard described Satan's Slave as "basically an archaic second feature" and "the sort of subject likely to turn up on Sunday afternoon children's television, with its kids-in-trouble/blame-the-older-generation theme."

[1] Criticising the "ponderous" script, the "predictable" action and the performances of the cast, the Telegraph described Satan's Slave as "mindless, stupefying trash [...] which destroys any reputation this country may have had as a producer of worthwhile films.

[22] Awarding two stars out of five, reviewer Fred Beldin comments that Satan's Slave "delivers extra gore and skin to keep the attention from wandering off a well-trodden road [...] There's no mystery for the viewer, because director Warren isn't shy about introducing the male lead with a scene in which he rapes and murders a flirty blonde."

[25] David Parkinson of Radio Times gives the film three stars out of five, concluding that Warren "ultimately overindulges in horror clichés and garish set pieces".

[26] TV Guide magazine describes it as a "vile shocker [...] full of unappetising gore effects",[23] while Time Out considers it an "absolute stinker", criticising its dialogue and "dragged-out" theme.

[28] Gary Raymond and Gray Taylor of the Wales Arts Review rank Satan's Slave 21st in their list of the "50 greatest" lesser-known horror films.

[4] Jo Botting of the British Film Institute website Screenonline opines that while the premise is "slightly old hat", the final plot twists create a "satisfying" ending.

[31] Despite calling the car crash "amusingly badly staged", commentator Ian Fryer believes that film's "attractive" locations and "excellent" performances make it "[look] like a much more expensive production than was actually the case."

"[20] Green writes that despite its "formulaic construction" the film is Warren's "most effective horror entry" and "head and shoulders above the stalk/slash tedium which would dominate the American industry within five years.

"[5] Reviewing the film for the website DVD Talk in 2004, Bill Gibron described Gough's character as a "grey Sunday drag of a villain" and Satan's Slave in general as a "near-immobile mess", adding: "With an ending that repeats, laps and then doubles back on itself, and an overall atmosphere of dismal dissatisfaction, the only suggestive thing about this movie is its titillating title.

He wrote: "[...] if you can get past the endless conversations, [the] lack of real suspense, the flawed feeling of familiarity and the dearth of any or all plot twists toward the end [...] then by all means saddle up and strap in".

[34] Rating the soundtrack nine out of ten, Unsworth describes Scott's score as "a stunning piece of work, melding some erratic styles perfectly and creating a genuine atmosphere of dread with each listen".