The Dark Knight was a 2008 superhero film directed by Christopher Nolan and starring Christian Bale as Batman and the late Heath Ledger as the Joker. It had an estimated budget of $185 million and went on to become one of the highest-grossing films of all time with over $1 billion in worldwide box office revenue. The film received widespread critical acclaim and earned Ledger a posthumous Oscar for his iconic portrayal of the Joker. Warner Bros. employed an extensive and innovative viral marketing campaign for the film that helped drive its commercial success.