The Dark Knight

"Batman Begins" had been a modest hit, taking nearly $400 million worldwide, but given that "Superman Returns" made slightly more in 2006, and failed to launch a franchise, Christopher Nolan had to really push the boat out for his second film. And he certainly did. "The Dark Knight" was longer, bigger and better than its predecessor, pioneering the use of IMAX cameras in feature films and introducing one of the most unforgettable performances in genre movies, in the shape of Heath Ledger's Joker, who became an instant icon the moment the first trailer appeared.

A sad and unexpected turn of events emerged not long after the film wrapped, when Ledger passed away in January of 2008, but one can only assume, or perhaps hope, that the film would have caught the public imagination in the same way had he lived; propulsive, epic, dark and unexpected, it was like nothing the superhero genre had ever produced. And it was a massive critical and commercial hit, taking over a billion dollars at the box office, and winning Ledger a posthumous Oscar, along with eight other nominations (the fact that the film missed out on a nod for Best Picture was widely credited with causing the Academy to expand the field to ten nominees the following year).

In short, it was something of a triumph. And after our look at "Batman Begins" yesterday, and ahead of the release of trilogy-closer "The Dark Knight Rises" tomorrow, we've assembled five things you might not know about the making of "The Dark Knight."

Dark Knight Bale Nolan
1. Nolan combined two planned sequels into one.
The success of "Batman Begins" meant that a sequel moved forward fairly swiftly, but the original film's co-writer David Goyer had already planned out two follow-ups, telling Premiere magazine before the release of the first film that he'd marked out a second film that would introduce both The Joker and Harvey Dent, and a third, which would open with the Joker attacking Dent at his trial, turning the DA into villain Two-Face. But Goyer wasn't available for full writing duties, with Nolan bringing on his brother Jonathan to pen the script, and as they started to focus on the film, they decided to combine Goyer's two outlined films into one. The director explained his commitment to giving the audience as much as possible to Empire Magazine shortly before the film's release: "Yes, but the ambition has to be to make a film that in some way moves on and develops the world you're in. Otherwise you're just making a TV show -- you're just making episodes of the same thing. When a sequel's done badly, you then take pot-shots at it and say, 'Why did they stuff all these extra characters in?' But when it works well, whether it's 'The Godfather Part II' or 'The Empire Strikes Back,' nobody complains. You have to try and expand it, and you have to try and do it well. In genre terms, if the first film had a very noirish quality to it, then what we've done with this film is taken on the dynamic of a story of the city, a large crime story. The broader canvas demands more characters to fill it. The audience accepts that type of storytelling where you're looking at the police, the justice system, the vigilante, the poor people, the rich people, the criminals. I'm hoping it's the sort of film that Michael Mann always did very well, like 'Heat'..."

The Dark Knight Aaron Eckhart
2. Mark Ruffalo was up to play Harvey Dent; Emily Blunt & Rachel McAdams were both considered to replace Katie Holmes.
Despite years of rumors, Heath Ledger was always Nolan's first choice to play The Joker ("Because he's fearless," he would say), and met with the actor before they had a script, announcing the casting in August 2006. But some of the other roles were a little more open. Mark Ruffalo, now celebrated for his portrayal of Bruce Banner/The Hulk in "The Avengers," confirmed in 2008 that he'd auditioned for the role of Harvey Dent, while Liev Schreiber and Ryan Philippe also met with Nolan about the part. Ultimately, though, it was Aaron Eckhart that won out, Nolan later explaining: "Ever since I saw him in 'In The Company Of Men,' I've thought he's an extraordinary actor. He seems so perfect for Harvey Dent because we wanted Harvey to be an all-American, kind of heroic figure; Aaron's got that kind of Robert Redford thing going on. He just embodies that kind of chiseled American hero. He does it so well. You just kind of relax in his presence when he's doing that character. But then there's this sort of edge to it all the way throughout, there's this thing just lurking under the surface..." Meanwhile, an alleged schedule conflict with flop heist film "Mad Money" meant Katie Holmes was unavailable. Rumors linked Emily Blunt and Rachel McAdams as potential replacements before Maggie Gyllenhaal won out -- something that would have been much more awkward had her brother Jake Gyllenhaal had a more successful audition for "Batman Begins" back in the day... Otherwise, Bob Hoskins and James Gandolfini were allegedly considered to play mobster Sal Maroni before Eric Roberts got a career lifeline, while rapper David Banner was up to play another crime boss, Gamble, with the part eventually taken by Michael Jai White. And Nolan actively pursued country-singer/actor Dwight Yoakam for not one, but two parts: as one of the corrupt Gotham City cops, and then for the part of the mob-affiliated bank manager in the opening scene. Yoakam couldn't work out his recording schedule, and William Fichtner memorably stepped in for the latter.