Before his iconic turn as the Joker in The Dark Knight Heath Ledger straight up hated comic book movies, until Christopher Nolan convinced him otherwise. While there had been fantastic takes on the Joker prior to The Dark Knight, including Jack Nicholson in Tim Burton's Batman and Mark Hamill's voice-over role in Batman: The Animated Series, Ledger's performance has come to be considered the defining take on Batman's most famous nemesis.
Ledger's Joker is both terrifying and hilarious, a sadistic madman who always appears to be two or three steps ahead of everyone else. It's almost easy to forget now, but Batman fans were seriously upset when Ledger was first cast. In the same way there was a backlash to Michael Keaton (Spider-Man: Homecoming) being cast as Batman in the 1980s, few could see Ledger in the role of the psychotic clown. Christopher Nolan was one person who saw Ledger's potential and together they would craft one of the all-time great screen villains.
Heath Ledger had never appeared in a comic book movie prior to The Dark Knight, and with good reason - he hated them. While Blade and X-Men gave the genre a shot in the arm, their quality during this era was still in question. For every Spider-Man by Sam Raimi, there was an Ang Lee's Hulk or Fantastic Four. In a 2006 interview with Dark Horizons, Ledger was blunt in his assessment of the genre. 'I actually hate comic book movies, like f***ing hate them, they just bore me s***less and they’re just dumb. But I thought what Chris Nolan did with Batman was actually really good, really well directed, and Christian Bale was really great in it.'
Christopher Nolan's Batman Begins rebooted the series after the fiasco of Batman & Robin and grounded the character in psychological realism. Nolan's Dark Knight trilogy is considered a major turning point in the perception of the genre, so it's easy to see why Ledger became attracted to the Joker when he was offered the role. His Joker isn't some campy, cackling madman, but a cunning sociopath who devises ingenious ethical dilemmas to put Batman, Commissioner Gordon, and Harvey Dent to the test.
The character seemingly appears out of thin air in the opening, and he wants to be seen as more of an idea than a man. He also defines himself through his conflict with Batman, and while he might be captured in the finale, he ultimately succeeds in corrupting Harvey Dent's soul. It's Ledger acting choices that make the character so compelling to watch, from his bizarre speech patterns and husky voice to his messy make-up. While the actor would draw on Alan Moore's graphic novel Batman: The Killing Joke and Malcolm McDowell's A Clockwork Orange, the final character is his unique invention.
Tragically, Ledger passed away before The Dark Knight was released, with his performance considered instantly iconic. He was posthumously awarded Best Supporting Actor at the 2009 Academy Awards for his work. 2008 would prove to be a major year for comic book movies, thanks to both The Dark Knight and Iron Man, which would kick off the MCU. Both Nolan and Ledger worked to craft a memorable villain to test Batman's moral code, and the late actor would leave behind a performance that is still being cited to this day. He took a risk with the sequel, diving into a genre he had a noted distaste for, but thankfully Christopher Nolan was able to convince him otherwise.