It was first published as a serial in Le Gaulois from 23 September 1909 to 8 January 1910, and was released in volume form in late March 1910 by Pierre Lafitte.

[1] The novel is partly inspired by historical events at the Paris Opera during the nineteenth century, and by an apocryphal tale concerning the use of a former ballet pupil's skeleton in an 1841 production of Carl Maria von Weber's Der Freischütz.

[4] The underground "lake" that he wrote about, in reality an enormous cistern, does exist beneath the opera house, and it is still used for training firefighters to swim in the dark.

[5][6] The serialized version contains an entire chapter ("L'enveloppe magique") that does not appear in the novel version—though much of its content was added in other chapters—and was not reprinted in English until 2014.

Raoul is led by a mysterious Opera House regular, 'the Persian', into Erik's secret lair in the bowels of the building.

Still, they end up trapped in a mirrored room by Erik, who threatens that unless Christine agrees to marry him, he will kill them and everyone in the Opera House by using explosives.

He allows 'the Persian' and Raoul to escape, though not before making Christine promise that she will visit him on his death day and return the ring he gave her.

He ran away from his native Normandy to work in fairs and caravans, schooling himself in the circus arts across Europe and Asia, and eventually building trick palaces in Persia and Turkey.

After being subcontracted to work on the Palais Garnier's foundations, Erik discreetly built his secret lair, complete with hidden passages and other tricks that allowed him to spy on the managers.

[8] Ribière makes note that Leroux was once a theatre critic and his brother was a musician, so he was knowledgeable about music and how to use it as a framing device.

[10] The mystery under investigation is the identity and motive of 'the Phantom' who lurks through the opera house, seemingly appearing out of nowhere as if by magic in inaccessible places.

The Phantom has a torture chamber where he kidnaps and kills people, and the walls of the chapel in the graveyard are lined with human bones.

[9] By the time Leroux published The Phantom of the Opera, he had already gained credibility as a crime mystery author in both French- and English-speaking countries.

He had written six novels prior, two of which had garnered substantial popularity within their first year of publication: The Mystery of the Yellow Room and The Perfume of the Lady in Black.

[15] The majority of the notability that the novel acquired early on was due to its publication in a series of installments in French, American, and English newspapers.

[16] There have been many literary and other dramatic works based on Leroux's novel, ranging from stage musicals to films to children's books.

Due to tensions on the set, there was a switch in directors and Edward Sedgwick finished the film while changing the direction of the movie.

With his second-hand copy of the novel and his artistic goals set on creating a major romantic piece, Lloyd Webber and his team wrote a musical that honored the original text while crafting a story that resonated deeply with audiences at the time.

Bill O'Connell, an assistant to film producers in New York at the time, contended for the show to appear as "based on" rather than "inspired by", as he viewed the latter as a minimization of Gaston Leroux's original involvement with the story.

Lawyers for producer Cameron Mackintosh and Webber's Really Useful Theatre Company responded, saying that it was never their intention "to fail to give appropriate prominence to the contribution of M. Leroux".