Harvey Dent was the District Attorney of Gotham City.
Originally working in Internal Investigations, Dent picked up the name "Harvey Two-Face" for being duplicitous when investigating people. He investigated many people who ended up working in James Gordon's Major Crimes Unit.
When he began running for the position of DA, Dent knew he would have to take on the mob. He was the verge of getting Al Rossi to testify against mob boss Sal Maroni, but in court Rossi had a change of heart and tried to shoot Dent. The gun jammed, and Harvey subdued Rossi and had him taken away, but Maroni went free.
Dent then decided to go after the mob's money, with the help of James Gordon and Batman. They lead raids on the mob's bank vaults, but found all the money had been moved by Mr Lau to Hong Kong. Batman kidnapped Lau and brought him back to Gotham. Dent and his girlfriend Rachel Dawes got Lau to indict all his fellow criminals in a RICO case, and Dent locked up half of the mob in a single day.
However, an anarchist named the Joker made a public demand that Batman unmask himself or people would die. Judge Janet Surrillo and Gillian Loeb were killed, and a fundraser that Bruce Wayne was holding for Dent was invaded by the Joker. Batman took Dent to the safety of a panic room and dealt with the situation, although the Joker got away.
Next the Joker named Mayor Anthony Garcia and Dent as targets, and during Loeb's funeral an attempt was made on Garcia's life. In the chaos, Dent grabbed Thomas Schiff who was working for the Joker and drove him to a secluded location. He used his lucky coin to decide whether Schiff lived or died, but Batman stopped him and told him his reputation was too important to be torturing people like that. Batman agreed to turn himself in.
Dent held a press conference and tried to convince people to hold out hope. When he was shouted down, he told people that he was the Batman and had himself arrested. As he was transported to jail, the Joker tried to kill him on the way. However Batman saved him, and James Gordon, who was thought dead, emerged from hiding to arrest the Joker. Dent was put into a car by Anna Ramirez, but he was kidnapped and taken to a warehouse filled with oil drums. He had a radio to communicate with Rachel Dawes, who was in the same situation, and he had to listen as Batman rescued him but Rachel was blown up. Dent was burnt on half of his body from the explosion.
In hospital, he refused skin grafts despite the immense pain. Gordon visited him, but Dent wouldn't listen and said he wouldn't hide who he was. He was then visited by the Joker, who gave him a gun and told him to introduce anarchy to Gotham. Dent got out of the hospital and foud Michael Wuertz, one of the corrupt men in Gordon's unit. Dent shot him, then found Sal Maroni. Maroni gave him Ramirez's name, and Dent shot his driver and crashed his car. Dent then found Ramirez, but spared her life on the flip of his coin. Finally, he kidnapped Gordon's wife and child and took them to the warehouse that Rachel died in.
Gordon and Batman showed up, trying to get Dent to drop the gun. He wouldn't listen, flipping a coin for each of their lives. He shot Batman, but spared his own life. He then pointed the gun at Gordon's son, and just before he pulled the trigger Batman flew at him and knocked him to the ground. Dent died from the fall, but Batman took the blame for his murders and he was hailed as a hero.