This is the first of the Corman-Poe cycle of films to NOT be based on anything written by Edgar Allan Poe...instead, screenwriter Charles Beaumont based an H.P. Lovecraft tale.
Synopsis from IMDb: Loosely based on H.P. Lovecraft's novel THE CASE OF CHARLES DEXTER WARD, this fright flick opens with a warlock placing a curse on a group of villagers about to burn him at the stake. Generations later, the warlock's descendant returns to the village to pick up where his ancestor left off. Written by Humberto Amador
The Haunted Palace, shot in 1963, released by American International Pictures, stars Vincent Price, Lon Chaney Jr. and Debra Paget (in her final film).
AIP marketed the film as "Edgar Allan Poe's The Haunted Palace", but the film was actually based on The Case of Charles Dexter Ward, a novella by H. P. Lovecraft (and this was the title under which the film was originally shot). The title The Haunted Palace is borrowed from the 6-stanza poem by Poe, published in 1839 (which was later incorporated into Poe's horror short story "The Fall of the House of Usher").
Odds and Ends from the interview in the Special Features of the MGM Midnite Movies DVD (Double Feature):
AIP had approached Corman wanting more Poe movies, but Roger suggested a Lovecraft story this time. AIP agreed at the time, but Corman thinks they planned all along to turn it into another of the Poe cycle films.
Chuck Beaumont was brought on to write and weaved in elements from multiple Lovecraft stories.
Francis Ford Coppela, Corman's assistant at the time, did a dialogue polish on the script and prepped actors on set. Corman was able to achieve a different look for this film, compared to the Poe pictures. For this Lovecraft story, he wanted starker lighting, to give The Haunted Palace a more realistic feel (as compared to the dreamier, more poetic Poe films).
Vincent Price and Corman talked in depth about his character (characters, really, as his character is also possessed by his great grandfather) prior to shooting, as a 15 day shooting schedule does not allow for deep discussions on set.
Corman said Lon Chaney (Jr.) was always his first choice for the character Simon Orne (AIP had suggested and were perhaps even leaning toward Boris Karloff, but Corman felt he wasn't quite right for the role).
Corman also said that this was Ronald Stein's score for The Haunted Palace was the best of all the Poe and related pictures he'd worked on with Roger.
Roger Corman had never intended to begin a Lovecraft cycle of films - The Haunted Palace was always intended as a one off to break up the Poe cycle and shake things up a bit.
"After the 18th-century portion of the story, Vincent Price recites lines 41 through 44 of the final stanza of the eponymous poem: "And travelers now within that valley though the red-litten windows see vast forms that move fantastically to a discordant melody," and the film ends with lines 45 through 48: "...While, like a ghastly rapid river, through the pale door, a hideous throng rush out forever and laugh - But smile no more."" -- and that was how they linked The Haunted Palace to anything remotely to do with Edgar Allan Poe and what gets it included in the Corman-Poe cycle.
Roger Corman wanted to do something different with The Haunted Palace, and this is why he selected a Lovecraft story. Apparently AIP changed the film's name to suggest continuity with the popular Poe series.
The film paired Vincent Price with Debra Paget and (at long last!) Lon Chaney Jr. (famous for playing The Wolf Man) -- this was Chaney's only appearance in a Corman film. He had co-starred with Price in Abbott and Costello Meet Frankenstein fifteen years earlier, but they didn't share any scenes (Price's role was a voiceover role as The Invisible Man). Chaney's role in The Haunted Palace was originally meant to be played by Boris Karloff, but Karloff had become ill while making Black Sabbath and couldn't play the part.
MORE FUN FACTS FROM WIKIPEDIA:
The set for the village of Arkham was quite small, and used forced perspective to appear larger. Both the front of the palace and the underground dungeon later appeared in Corman's The Terror, which was shot on sets from other AIP films.
Francis Ford Coppola provided additional dialogue for the film.
Clips from The Haunted Palace are among the stock footage from various Corman features used for the Vincent Price film Madhouse (1974), in which Price plays a horror film actor. The clips are presented as the early work of Price's character.