When news emerged of Brokeback Mountain star Heath Ledger’s untimely accidental death back in January this year, many film fans were shocked by the loss of such a promising, rising star whose portrayal of a closeted gay man changed perceptions of homosexuality across the world.

Selfish thoughts? Certainly. But Ledger died just as Batman fans had come to accept him in the role of the Joker. It was a time when they had really started to look forward to seeing what he was going to do with the part, thanks to the release of early trailers and publicity photos from the set. The thought that Ledger may have died before finishing what was always going to be one of the most anticipated films of the year was too much to contemplate, even if such fears proved groundless.

Ledger’s casting had not initially been popular. Jack Nicholson’s turn as the Joker in Tim Burton’s iconic 1989 Batman is still counted as one of the best on-screen villains of all time. So much so, in fact, that when the Joker’s return was hinted at in the closing scene of Batman Begins, many fans of the series groaned silently to themselves at the prospect of a botched revival. Countless possible actors were mooted by fans, from Adrien Brody and Paul Bettany through Robin Williams, Christian Slater and even Jack Nicholson himself.

Indeed, Nicholson is on public record saying that he was “furious” not to have been asked to reprise the role. In numerous interviews, Ledger spoke of how difficult he found it to create a take on the character that was not at least in part inspired by Nicholson’s interpretation. For the fans, however, Ledger seemed not only too good-looking and too muscle-bound but also too conventional for a character portrayed in the comics as a truly bizarre-looking, mass-murdering psychopath. Could an actor famous primarily for his jocular good humour really pull off the kind of loveable darkness necessary for such a complex villain?

As it stands, Ledger’s performance in The Dark Knight makes his untimely death just that much more tragic, because it turns out to be the best of his career. Yes, this is a comic book movie, but the Batman comics have, at least for the last couple of decades, always had more psychological depth than their more colourful fellows. After the slapstick silliness of the 1960s Adam West-starring TV series, in the 1980s the character took a turn towards the more adult, with Tim Burton’s 1989 film a reflection of this new-found darkness, and Batman Begins continuing the trend with aplomb.

The Dark Knight is, despite initial fans fears, everything that could be hoped for from a sequel to Batman Begins. The old cast – Christian Bale as Batman, Michael Caine as his butler Alfred, Gary Oldman as the future Commissioner Gordon and a supporting cast including Morgan Freeman, Maggie Gyllenhaal and more – all lend sufficient gravitas to a superhero flick that is very much not for the kids. And despite the loss of Ledger, there is much promise for the franchise to come with the introduction of Aaron Eckhart as Harvey Dent, the lawyer ally of Batman who in the comics goes on to become the villain Two Face.

Throughout, it is Ledger who dominates the film, just as Nicholson dominated the 1989 Batman. Where on his death Ledger was already being mourned for his unfulfilled promise, The Dark Knight serves to heighten that sense of a great actor lost, while also acting as a perfect epitaph for a career cut tragically short. On the basis of this film, Heath Ledger truly could have been one of the greats. Not to be missed.