The Dark Knight is a 2008 superhero film directed by Christopher Nolan from a screenplay he co-wrote with his brother Jonathan. Based on the DC Comics superhero, Batman, it is the sequel to Batman Begins (2005) and the second installment in The Dark Knight Trilogy. The plot follows the vigilante Batman, police lieutenant James Gordon, and district attorney Harvey Dent, who form an alliance to dismantle organized crime in Gotham City. Their efforts are derailed by the Joker, an anarchistic mastermind who seeks to test how far Batman will go to save the city from chaos. The ensemble cast includes Christian Bale, Michael Caine, Heath Ledger, Gary Oldman, Aaron Eckhart, Maggie Gyllenhaal, and Morgan Freeman.

Warner Bros. Pictures prioritized a sequel following the successful reinvention of the Batman film series with Batman Begins. Christopher and Batman Begins co-writer David S. Goyer developed the story elements, making Dent the central protagonist caught up in the battle between Batman and the Joker. In writing the screenplay, the Nolans were influenced by 1980s Batman comics and crime drama films, and sought to continue Batman Begins' heightened sense of realism. From April to November 2007, filming took place with a $185 million budget in Chicago and Hong Kong, and on sets in England. The Dark Knight was the first major motion picture to be filmed with high-resolution IMAX cameras. Christopher avoided using computer-generated imagery unless necessary, insisting on practical stunts such as flipping an 18-wheel truck and blowing up a factory.

The Dark Knight was marketed with an innovative interactive viral campaign that initially focused on countering criticism of Ledger's casting by those who believed he was a poor choice to portray the Joker. Ledger died from an accidental drug overdose in January 2008, leading to widespread interest from the press and public regarding his performance. It broke several box-office records and became the highest-grossing 2008 film, the fourth-highest-grossing film of its time, and the highest-grossing superhero film.

Source: Wikipedia