It has been eight years since the sequel to Batman Begins hit cinemas, bringing with it one of the most iconic characters in a superhero movie.
Heath Ledger's The Joker character changed the way villains are portrayed onscreen and will perhaps never be matched.
Here are 12 things that your (probably) didn't know about The Dark Knight...
1. Christopher Nolan ramped up Bale's Batman growl
The often mocked and parodied Batman growl that gave Christian Bale a sore throat wasn't all Bale's work.
While performing as Batman, Bale toned down his voice from Batman Begins and director Christopher Nolan heightened it to a rougher, grittier sound during the editing process.
2. The opening scene's bus crashing through the wall was a logistical nightmare
Unbeknownst to the stunt team, they weren't able to just crash the bus through the wall.
Instead, they had to take the bus apart and reassemble it inside the building, which was a disused post office.
A large fake wall was then put up to conceal the bus, which was then propelled backwards through the false wall with an air cannon.
Sounds like a right hassle.
3. Heath Ledger was the only choice to play The Joker
While casting the role of Batman for Batman Begins, Heath Ledger auditioned, but both he and Christopher Nolan agreed that he was the wrong part for the role.
While casting The Joker, Nolan met several actors, all of which were reluctant to take the role because of the popularity of Jack Nicholson's portrayal of The Joker.
When Nolan met Ledger again, the director realised he would be the perfect choice for the clown prince of crime.
Paul Bettany, Lachy Hulme, Adrien Brody, Steve Carell and Robin Williams all publicly expressed an interest in the role, with no idea that Nolan always wanted Ledger for the role.
At the time, Ledger's casting proved quite controversial, and when asked why Nolan cast the Australian pretty boy, Nolan replied simply: "Because he's fearless."
4. Heath Ledger went super hardcore in his preparation
It's well known that Ledger locked himself away in a motel room for six weeks to consider the psychology of the character.
In that time, attempting to have his career vastly different from Nicholson's 1989 Joker, he developed The Joker’s tics, voice, and sadistic laugh
Ledger based his appearance on the chaotic, dishevelled look of The Sex Pistols' Sid Vicious and the unhinged mannerisms on Malcolm McDowell's portrayal as Alex De Large in A Clockwork Orange.
He also worked with a vocal coach to master The Joker's voice - they looked at ventriloquist dummies to zero in on the disconnected, mocking quality (and not like Tom Waits in a 1970s interview - which was recently claimed in a YouTube upload).
5. Aaron Eckhart put just as much preparation for Harvey Dent/Two-Face
Eckhart described Harvey Dent as, "simultaneously coming from, and being apart from, the same world as Batman."
He prepared for this by "looking for the similarities and the tension between the two; to find what's similar to Batman and then what's opposite to him."
As well as this he studied what happens psychologically to burn victims, as well as studying split personalities.
6. Jack Nicholson told Heath Ledger some really heavy stuff about playing The Joker
Ledger personally interviewed Jack Nicholson about his role in 1989's Batman, and Nicholson told him "The role of being The Joker will haunt you; the role is so dark that you'll probably won't be able to sleep, but enjoy the role as the Clown Prince of Crime, because it's nothing, but good fun." Which is a bit unnecessary.
Michael Caine thinks that Hedger's portrayal topped Nicholson's Joker, stating Nicholson's version was “benign but wicked, maybe a killer old uncle.
"Heath's gone in a completely different direction to Jack," Caine said in interviews before the film's release, “he's like a really scary psychopath"
7. The Joker's costume had rock music inspirations
Costume designer Lindy Hemming drew inspiration from the likes of Vivienne Westwood, John Lydon, Iggy Pop, Pete Doherty and Alexander McQueen to update the Joker's trademark purple suit from the comics.
Her aim was to represent Ledger's generation with "a younger, trendier look" for The Joker's well-known look.
8. If Christopher Nolan knew he was going to make a third film; he wouldn't have introduced Harvey Dent (or killed him)
While directing The Dark Knight, Christopher Nolan had no intentions of making a third film, but back in 2005, the film's co-writer David Goyer revealed the plot for a possible third film, if Nolan knew he was going to make a trilogy:
“The next one would have Batman enlisting the aid of Gordon and [Harvey] Dent in bringing down the Joker, but not killing him, which is a mistake they made in the first one. In the third, the Joker would go on trial, scarring Dent in the process.”
If Nolan had have planned for a trilogy instead of making The Dark Knight as a standalone movie, it is believed that Harvey Dent would have been saved for the third film and The Joker would have turned into Two-Face early on, with him becoming the third film's primary villain - instead this was worked into The Dark Knight's story.
9. Christopher Nolan broke a $500,000 camera while filming
While filming The Joker's chase scene with the SWAT vans, Christopher Nolan managed to break a $500,000 camera - one of only four in the world at that time.
Interestingly, during the filming of The Dark Knight Rises, Anne Hathaway's stunt double drove the Batpod directly into another IMAX camera rig, which destroyed that one as well. Check out this video if you're interested in seeing a shaky video of the incident.
10. The Joker's backstory would never be told
Despite The Joker providing a couple of contradicting stories on how he got his scars, and a very credible fan theory about him coming from a military background, we don't find out anything about The Joker's past.
This was done on purpose as writers Christopher Nolan, his brother Jonathan and David S. Goyer decided not to explore The Joker's origins so that they could present the character as an 'absolute'.
11. An ill-advised PR stunt for the film went terribly (and unsurprisingly) wrong
To promote the film, a website related to the film sent out several cakes from 'The Joker'.
The cake had a mobile phone inside which made the cake vibrate and the cake also had wires sticking out of it to make it look like a bomb.
Security services at a news station which received one of these 'bomb cakes' thought it was an actual terrorist attack and the entire building was evacuated.
12. The Dark Knight received the most complaints to the BBFC of any film in the 2000s
Despite its dark and unsettling themes, the BBFC gave The Dark Knight a 12A certificate, which resulting in a deluge of complaints.
The film received 364 complaints, mostly from parents that brought younger children along - owing to the certificate - which resulted in a swathe of perturbed pre-teens.
While that doesn't sound like a lot of grumpy correspondences, it accounts for 40 per cent of the BBFC's complaints in 2008.
In a national newspaper, Former leader of the Conservative Party Iain Duncan Smith wrote that he was "astonished that the board could have seen fit to allow anyone under the age of 15 to watch the film."