History Trivia / HarryPotterAndThePrisonerOfAzkaban

** Creator/TildaSwinton was the first choice to play Professor Trelawney. This would have been HilariousInHindsight with ''Literature/TheLionTheWitchAndTheWardrobe'' the next year.

* DeletedRole: Sir Cadogan, played by Paul Whitehouse, was cut almost completely out of the film, although you can still see him jumping through several paintings behind Ron, Harry and Hermione during the Fat Lady's disappearance.

* DummiedOut: The GBA version of the game has remnants of a ''VideoGame/{{Tapper}}'' clone [[http://tcrf.net/Harry_Potter_and_the_Prisoner_of_Azkaban_%28Game_Boy_Advance%29#Unused_Minigame floating about]] in the data. You can cheat your way into it, but its {{Unwinnable}}, as the "catch the mug" routine was either removed or never finished.

* CreatorsFavoriteEpisode: Creator/DanielRadcliffe named this as his favourite book in the series.

** Creator/MNightShyamalan was offered the job of directing the film, but turned it down in favor of ''Film/TheVillage''.

* CreatorCouple: Creator/LennyHenry and Creator/DawnFrench were married at the time.

** Creator/MichaelGambon replaces the late Richard Harris. Dawn French also replaces Elizabeth Spriggs as the Fat Lady.

* The only book in the series where no character dies, and also where Voldemort does not appear in any shape or form. Unless you count Harry hearing Voldemort's laughter in a memory.

** Creator/IanMcKellen was asked to play Dumbledore after Richard Harris's death, but turned it down for the pressure he'd felt from playing [[Film/LordOfTheRings Gandalf]]. Still, he later said he regretted not having a role in the franchise. (Amusingly, Harris had a famous one-sided enmity in real life with [=McKellen=], as he had reportedly lobbied strongly for the role of Gandalf and believed Ian had robbed him of it.) Creator/ChristopherLee and Creator/PeterOToole were considered for the part, while Creator/RichardAttenborough lobbied for it but was turned down.

** Alfonso Cuaron wanted the Dementors to be achieved through puppetry. Once it became clear that wouldn't be feasible, he switched to CGI. However they did use footage of puppets underwater for reference when creating the CGI.

** Creator/GuillermoDelToro was approached to direct. He opted to work on ''{{Film/Hellboy}}'' instead, but recommended his friend Alfonso Cuaron, and the rest is history.

* MoneyDearBoy: Creator/GaryOldman took the role of Sirius because he had not done a film in over a year and needed the work desperately. This turned out to be a positive version of the trope though as he gave a great performance, became good friends with Creator/DanielRadcliffe while filming, and happily came back for the sequels.

* CreatorPreferredAdaptation: Creator/JKRowling said this was her favourite of the films, claiming she got goosebumps watching some parts of it. She also mourned the fact that she didn't think of the shrunken head.
* DeletedRole: Sir Cadogan, played by Paul Whitehouse, was cut almost completely out of the film. You do still see Sir Cadogan jumping through several paintings behind Ron, Harry and Hermione during the Fat Lady's disappearance.
* MoneyDearBoy: Creator/GaryOldman took the role of Sirius because he desperately needed the work, not having done a film in over a year. This turned out to be a positive version of the trope though as he gave a great performance, became good friends with Creator/DanielRadcliffe while filming, and happily came back for the sequels.
* TheOtherDarrin: Creator/MichaelGambon replaces the late Richard Harris. Dawn French also replaces Elizabeth Spriggs as the Fat Lady. An inversion happened with Creator/WarwickDavis. As Flitwick wasn't in the script and Cuaron wanted to use Davis anyway, he had him play the conductor for the school choir. Later films retconned this to being Flitwick anyway. This almost happened to Dudley, as Harry Melling had lost a lot of weight in between films. They ended up just putting him in a fat suit.

* TroubledProduction: Huge amounts of heavy rainfall nearly destroyed the sets. Helicopters had to bring bags of gravel in to prevent them from being washed away. There were numerous other weather-related difficulties from shooting on location in Scotland. Alfonso Cuaron ended up loving the resulting look of the film however.

** Creator/IanMcKellen was asked to play Dumbledore after Richard Harris' death, but turned it down for the pressure he'd felt from playing [[Film/LordOfTheRings Gandalf]]. Still, he later said he regretted not having a role in the franchise (interestingly, Harris had a famous personal enmity in real life with [=McKellen=], and he had reportedly lobbied for the Gandalf role which was ultimately given to Ian). Creator/ChristopherLee and Creator/PeterOToole were considered for the part, while Creator/RichardAttenborough lobbied for it but was turned down.

** ''Creator/GuillermoDelToro'' was approached to direct. He opted to work on ''{{Film/Hellboy}}'' instead, but recommended his friend Alfonso Cuaron and the rest is history.

** Alfonso Cuaron wanted the Dementors to be achieved through puppetry. Once it became clear that wouldn't be feasible, they switched to CGI. However they did use footage of puppets underwater for reference when creating the CGI.

* TheOtherDarrin: Creator/MichaelGambon replaces the late Richard Harris as Dumbledore following the latter's death in 2002. Dawn French also replaces Elizabeth Spriggs as the Fat Lady. An inversion happened with Creator/WarwickDavis. As Flitwick wasn't in the script and Cuaron wanted to use Davis anyway, he had him play the conductor for the school choir. Later films retconned this to being Flitwick anyway. This almost happened to Dudley, as Harry Melling had lost a lot of weight in between films. They ended up just putting him in a fat suit.

* SoMyKidsCanWatch: Creator/EmmaThompson took the role of Professor Trelawney to impress her daughter.

* TheOtherDarrin: Creator/MichaelGambon replaces the late Richard Harris as Dumbledore following the latter's death. Dawn French also replaces Elizabeth Spriggs as the Fat Lady. An inversion happened with Creator/WarwickDavis. As Flitwick wasn't in the script and Cuaron wanted to use Davis anyway, he had him play the conductor for the school choir. Later films retconned this to being Flitwick anyway. This almost happened to Dudley, as Harry Melling had lost a lot of weight in between films. They ended up just putting him in a fat suit.

* TheOtherDarrin: Creator/MichaelGambon replaces the late Richard Harris as Dumbledore. Dawn French also replaces Elizabeth Spriggs as the Fat Lady. An inversion happened with Creator/WarwickDavis. As Flitwick wasn't in the script and Cuaron wanted to use Davis anyway, he had him play the conductor for the school choir. Later films retconned this to being Flitwick anyway. This almost happened to Dudley, as Harry Melling had lost a lot of weight in between films. They ended up just putting him in a fat suit.

* AcclaimedFlop: By ''Harry Potter'' standards, mind you. It is, perhaps, the most critically acclaimed movies of the eight (second only to ''Deathly Hallows - Part 2'' on Website/RottenTomatoes) but ''Prisoner'' is the series' lowest-grossing installment, at ''[[FirstWorldProblems $800 million]]''.

** The original script called for Hermione to slap Draco as she does in the book. During a rehearsal, Creator/EmmaWatson actually slapped Creator/TomFelton with full force. She later said she had no idea why she did it, and felt horrible about it afterwards.

* BTeamSequel: Creator/ChrisColumus stepped down as director due to family commitments. He stayed on as producer and then vacated the series.

* ActorAllusion: Timothy Spall plays a man who can transform into a rat. He previously voiced a rat in ''WesternAnimation/ChickenRun''.
* ActorInspiredElement: Gary Oldman suggested Sirius's hairstyle.
* AwesomeDearBoy: David Thewlis took the role of Lupin after Ian Hart assured him it was "the best part in the book" and because he was excited to make a children's film. He reportedly enjoyed filming very much.
* CreatorCameo: Alfonso Cuaron has a cameo in the scene in Madam Rosmerta's tavern. He's the man sitting down, holding two lit candles.
* CreatorPreferredAdaptation: JK Rowling said this was her favourite of the films, claiming she got goosebumps watching some parts of it. She also mourned the fact that she didn't think of the shrunken head.
* MoneyDearBoy: Gary Oldman took the role of Sirius because he desperately needed the work, not having done a film in over a year. This turned out to be a positive version of the trope though as he gave a great performance, became good friends with Daniel Radcliffe while filming, and happily came back for the sequels.
* TheOtherDarrin: Michael Gambon replaces the late Richard Harris as Dumbledore. Dawn French also replaces Elizabeth Spriggs as the Fat Lady. An inversion happened with Warwick Davis. As Flitwick wasn't in the script and Cuaron wanted to use Davis anyway, he had him play the conductor for the school choir. Later films retconned this to being Flitwick anyway. This almost happened to Dudley, as Harry Melling had lost a lot of weight in between films. They ended up just putting him in a fat suit.

* RealLifeWritesThePlot: Goyle has a smaller role in this, due to his actor breaking his arm and being unable to film certain scenes. Bronson Webb was cast as a Slytherin boy called Pike to fill Goyle's role for those scenes.

* SoMyKidsCanWatch: Emma Thompson took the role of Professor Trelawney to impress her daughter.

** Alfonso Cuaron intended for the choir to show tiny people jumping on the keys. JK Rowling vetoed that, claiming tiny people were alien to the HP Universe. He also wanted to put a graveyard in, but she vetoed that as well - claiming it would contradict an important plot point in later books. She did however allow him to place a sundial on the grounds.
** The original script called for Hermione to slap Draco as she does in the book. During a rehearsal, Emma Watson actually slapped Tom Felton with full force. She later said she had no idea why she did it, and felt horrible about it afterwards.
** Ian [=McKellen=] was asked to play Dumbledore after Richard Harris' death, but turned it down for the pressure he'd felt from playing [[Film/LordOfTheRings Gandalf]]. Still, he later said he regretted not having a role in the franchise (interestingly, Harris had a famous personal enmity in real life with [=McKellen=], and he had reportedly lobbied for the Gandalf role which was ultimately given to Ian). Christopher Lee and Peter O'Toole were considered for the part, while Richard Attenborough lobbied for it but was turned down.
** Tilda Swinton was the first choice to play Professor Trelawney. This would have been HilariousInHindsight with ''Literature/TheLionTheWitchAndTheWardrobe'' the next year.
** ''Guillermo Del Toro'' was approached to direct. He opted to work on ''{{Film/Hellboy}}'' instead, but recommended his friend Alfonso Cuaron and the rest is history.

** Lucius Malfoy would have appeared for Buckbeak's execution scene, but Jason Isaacs was unavailable.

** Ian [=McKellen=] was asked to play Dumbledore, but turned it down after the pressure he'd felt from playing [[Film/LordOfTheRings Gandalf]]. He later said he regretted not having a role in the franchise. Christopher Lee and Peter O'Toole were considered for the part. Richard Attenborough lobbied for it but was turned down.

* MoneyDearBoy: Gary Oldman took the role of Sirius because he desperately needed the work, not having done a film in over a year.

* CreatorPreferredAdaptation: JK Rowling said this was her favourite of the films, claiming she got goosebumps watching some parts of it. She also mourned the fact that she didn't think of the shrunken heads.

* AcclaimedFlop: By ''Harry Potter'' standards, mind you. It is perhaps, the most critically acclaimed movies of the eight (second only to ''Deathly Hallows - Part 2'' on Website/RottenTomatoes) but ''Prisoner'' is the series' lowest-grossing installment, at ''[[FirstWorldProblems $800 million]]''.

* CreatorPreferredAdaptation: JK Rowling said this was her favourite of the films, claiming she got goosebumps watching some parts of it.

* AcclaimedFlop: Despite being one of the most critically acclaimed movies of the eight (second only to ''Deathly Hallows - Part 2'' on Website/RottenTomatoes), ''Prisoner'' is the series' lowest-grossing installment, barely managing $800 million.

* Creator/GaryOldman is well-known for playing villains, so when he was cast as Sirius Black, a mass-murderer after Harry, no one was surprised. By the end, it's revealed that Sirius never murdered or betrayed anyone, and in later movies he becomes the closest thing Harry has to family (naturally, this came as no surprise to viewers who'd already read the books).