In many fans' opinions, The Dark Knight Trilogy -- starring Christian Bale as the Caped Crusader -- is the pinnacle of Warner Bros.' foray into the ever-expanding superhero movie genre. According to director Christopher Nolan, though, that could have less to do with Bale's Batman and more to do with his extensive rogues gallery.

“To me, each film is a different genre,” Nolan told Variety. “They tend to be defined by the villain.”

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Speaking about 2005's Batman Begins, Nolan explained that Liam Neeson's Ra's al Ghul "is an appropriate adversary. He’s a mentor-turned-enemy.” As for Heath Ledger's Joker in 2008's The Dark Knight, Nolan described him as "a terrorist, an agent of chaos set loose.” Finally, the director addressed Tom Hardy's Bane in 2012's The Dark Knight Rises, calling the film a "historical epic" and Bane a "militarist foe."

"Yes, it's a superhero, but it's based on ideas of guilt, fear, these strong impulses that the character has," Nolan continued. "Bruce Wayne doesn't have any super powers other than extraordinary wealth. But really, he's just someone who does a lot of push-ups. In that sense, he's very relatable and human. I think that's why I gravitated towards it."

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Batman Begins' decidedly darker tone compared to the previous on-screen portrayals of the Caped Crusader wowed critics, and the film was nominated for an Academy Award for Best Cinematography. Seven years later, The Dark Knight Rises managed to outperform both its predecessors at the box office, grossing over $1.08 billion worldwide. However, most are in agreement that 2008's The Dark Knight is arguably the best chapter in the trilogy, and Heath Ledger's bone-chilling take on the Clown Prince of Crime even earned him a posthumous Academy Award for Best Supporting Actor.