Christian Bale as Bruce Wayne / Batman:A billionaire socialite who, after witnessing his parents' death in a mugging at age 8, travels around the world seven years before returning home to inherit his family company Wayne Enterprises whilst operating at night as a bat-masked vigilante bringing justice upon the criminal underworld of Gotham City.Bale was relatively unknown when cast. Before he was confirmed on September 11, 2003, having expressed interest in the role since Darren Aronofsky was planning his own film adaptation, Eion Bailey, Henry Cavill, Billy Crudup, Hugh Dancy, Jake Gyllenhaal, Joshua Jackson, Heath Ledger, David Boreanaz and Cillian Murphy took interest in it as well. Amy Adams served as the casting reader for the casting of Bruce Wayne / Batman in a favor to the casting director. Bale felt the previous films underused Batman's character, overplaying the villains instead. To best pose as Batman, Bale studied graphic novels and illustrations of the superhero. Director Nolan said of Bale, "He has exactly the balance of darkness and light that we were looking for." Goyer stated that while some actors could play a great Bruce Wayne or a great Batman, Bale could portray both radically different personalities. Bale described the part as playing four characters: the raging Batman persona; the shallow playboy façade Bruce uses to ward off suspicion; the vengeful young man; and the older, angrier Bruce who is discovering his purpose in life. At his audition, Bale wore the bat suit (minus the cape, which has been missing for some time) Val Kilmer donned for 1995's Batman Forever. Bale's dislike of his costume, which heated up regularly, helped him get into a necessarily foul mood. He said, "Batman's meant to be fierce, and you become a beast in that suit, as Batman should be – not a man in a suit, but a different creature." Since he had lost a great deal of weight in preparation for his role in The Machinist, Bale hired a personal trainer to help him gain 100 pounds (45 kg) of muscle in the span of only a couple of months to help him physically prepare for the role. He first went well over the weight required and created concern over whether he would look right for the part. Bale recognized that his large physique was not appropriate for Batman, who relies on speed and strategy. He lost the excess weight by the time filming began. Bale trained in Wing Chun Kung Fu under Eric Oram in preparation for the movie.Gus Lewis as Young Bruce Wayne.Michael Caine as Alfred Pennyworth:A trusted butler to Bruce's parents, who continues his loyal service to their son after their deaths as his closest confidant. Nolan felt Caine would effectively portray the foster father element of the character. Although Alfred is depicted in the film as having served the Wayne family for generations, Caine created his own backstory, in that before becoming Wayne's butler, Alfred served in the Special Air Service. After being wounded, he was invited to the position of the Wayne family butler by Thomas Wayne because, "He wanted a butler, but someone a bit tougher than that, you know?"Liam Neeson as Henri Ducard / Ra's al Ghul:The leader of the League of Shadows, an ancient society that uses injustice to punish the corrupt and decadent, who goes undercover as an associate of the League and trains Bruce in martial arts, later revealing himself in the film's climax. Writer David Goyer said he felt he was the most complex of all the Batman villains, comparing him to Osama bin Laden; "He's not crazy in the way that all the other Batman villains are. He's not bent on revenge; he's actually trying to heal the world. He's just doing it by very draconian means." Gary Oldman was first choice for the part, but ended up playing James Gordon instead. Guy Pearce, who collaborated with Christopher Nolan on Memento (2000), reported that the pair had discussions about him playing the role, but both of them decided that he was too young for the part. Neeson is common

Question: Cillian Murphy was asked to play which character from the Arkham Asylum?
Answer: Scarecrow