"Two faces... just like this mirror. Two faces and two minds. Can't fix them until they're one. Right? Right? "-- Two-Face 

History

Two-Face was once Harvey Dent, the District Attorney of Gotham City, and a close personal ally of Batman. However, after a criminal, "Boss" Moroni, threw acid in his face, severely disfiguring one half but leaving the other unharmed, he became the insane crime boss Two-Face.

Origins

Harvey Dent was born into a life of hardship. Growing up in a lower-class family, Dent was raised with an instinctive dislike and mistrust for the upper-class. His violent, cruel and mentally ill father frequently bullied and abused him as a child, with his favorite game being flipping his double-headed coin promising to spare the child a beating if the coin landed tails. These harsh surroundings resulted in Dent developing repressed mental illnesses of his own, such as bipolar disorder and schizophrenia. His hard work ethic, however, allowed him to rise to become a lawyer and, eventually, the District Attorney. He was nicknamed "Apollo" by the media, because he was charming, good-looking and seemingly untouchable. He was dedicated to his job of upholding law and order, and became one of the first supporters, allies and even friends of the Batman. At the time of his job as D.A., the worst criminal threat in Gotham was the nigh omnipotent mafia boss Carmine Falcone, "The Roman." After Dent struck several blows to the Roman's Empire, Falcone hired Mickey "The Mink" Sullivan to eliminate the D.A. However, the attempt by Mickey's gang to take out Dent failed. He forged a triumvirate with Batman and Commissioner James Gordon to bring the man down within the law, no matter what the cost. His slightly angrier temperament led Batman and Gordon to distrust him slightly, believing there was a possibility he might be the mysterious "Holiday" killer who was gunning down mob members at the time (including Mickey and his gang). The alliance ended tragically whenSal Maroni, believing Dent to be responsible for the death of his father, threw acid in his face during a trial. Dent was horribly scarred on the left side of his face. Dent escaped from the hospital and descended into madness. He became obsessed with duality and opposites, and developed a second persona, the villainous Two-Face, to compliment the law & order obsessed Harvey Dent. As Two-Face, his trademark was crimes involving the number two. His obsession even shows in his clothes, which are usually composed of two halves made out of very different materials. He carries a double-sided coin with one side scratched at all times. His first crime as Two-Face was the killing of his corrupt Assistant District AttorneyVernon Wells and Carmine Falcone. (Two-Face failed to kill Maroni, as he had already been assassinated at this point by Falcone's son Alberto.) Two-Face was eventually incarcerated in Arkham Asylum. Two-Face next escaped from Arkham Asylum on the following Halloween (possibly aided by Maroni's twin sons Pino and Umberto), stole his old case files, and began the dismantling of the Falcone crime family. A new killer began following The Holiday's pattern, only this time not killing mobsters but cops. Dent saved Jim Gordon from the Hangman, as the new murderer was dubbed, and told Gordon he was not the Hangman. He continued using his alliance to the rest of Batman's Rogues Gallery to dismantle the mob. It was during this time he was having an affair with his successor as District Attorney,Janice Porter, a person he used to meet back at Gotham University when he was a professor. Porter was soon killed by Two-Face when she said she loved him. Over the the course of the year, he finally succeeded in eliminating Carmine Falcone's successor, his daughter Sofia Gigante Falcone who was revealed to be the Hangman the entire time, and even though he was taken in, Two-Face had permanently shifted the balance of power in Gotham's underworld from the mob to the so-called "costumed freaks."

History with "The Boy Wonder"

Two-Face was the reason Bruce Wayne fired Dick Grayson, then Robin, from being his partner. After a failed attempt to rescue the then D.A. from Two-Face, who also had The Dark Knight captive as well, Two-Face brutally beat Dick, scaring Batman into firing Dick. Later, Two-Face killed a henchman who happened to be the father of Jason Todd, the second Robin. After Todd's death, Two-Face resurfaced and carried out a number of obviously two-related crimes. Batman became increasingly obsessed with catching him, as Two-Face became fixed on taking down Batman. Meanwhile, Tim Drake tracked down Dick Grayson (who by then was operating as Nightwing and taking a break from his position as leader of the Teen Titans) and attempted to convince him to return to his position as Robin for Batman's safety. Nightwing refused and followed various clues left by Batman, meeting up with him for the attack on Two-Face's base. Two-Face collapses the building, trapping them. In the Batcave, Tim steals a Robin costume goes to the rescue. His intervention saves Batman and Nightwing and helps them apprehend Two-Face, leading Batman to accept him as the third Robin.

Modern Age

In the aftermath of the earthquake that left Gotham City in a shambles, Two-Face kidnapped Commissioner Gordon and put him on trial for his actions during No Man's Land, with Two-Face as both judge and prosecutor. Gordon played upon Two-Face's split psyche to demand Harvey Dent as his defense attorney. Dent cross-examined Two-Face and won an acquittal of Gordon. It was also during this time that Two-Face met GCPD detective Renée Montoya. Montoya was able to reach the Harvey persona in Two-Face, and was kind to him. He fell in love with her, though the romance was one-sided. After the earthquake that ravaged Gotham, Two-Face outed her as a lesbian and framed her for murder, hoping that if he took everything from her she would be left with no choice but to be with him. Montoya was furious, and the two fought for control of his gun until Batman intervened, putting Two-Face back in Arkham Asylum. A short time later, Two-Face met the brilliant surgeon, Dr. Thomas Elliot. Although Elliot specialized in neurosurgery, he was competent enough to repair Dent's face via plastic surgery. Dent's sanity was restored, and the menacing "Two-Face" persona seemed to be gone forever. Thomas Elliot was also the villain known as Hush, and he had hoped to manipulate Harvey into acting as one of his many pawns in a campaign against Batman. With renewed sanity, the former D.A. stood by the side of law and order and betrayed Hush, catching him in enough time to save Batman's life, and shooting him into the Gotham river.

One Year Later/The Return of Two-Face

Having regained his trust, Dent was trained and conditioned by Batman to act as Gotham's primary vigilante protector when he, Robin and Nightwing all took a one-year hiatus to train during the Lost Year. When Batman returned, a series of murders occurred implicating Harvey and involving Two-Face's M.O.. When confronted on the issues by Batman, in his anger at being distrusted, the Two-Face persona resurfaced, and talked Dent into scarring his face and returning to his life of crime. Following the supposed death of Batman during the Final Crisis, Two-Face became one of the two major contenders for control of the Gotham underworld, fighting with the Penguin. However, a new Black Mask made his own play for power, recruiting a number of Arkham inmates and play his attacks on the two as attacks made by the other.

Battle for the Cowl

Two-Face realizes that there's another person under the cowl. He hires a teleporter and manages to infiltrate the Batcave. When the new Batman investigates the cave, he is ambushed by Two-Face with tranquilizer darts, and in a hallucination he sees Dent in a red and black Two-Face themed Batman costume. However, Alfred Pennyworth saved the hero from Two-Face's torture after he subdues his accomplice, and with his help Batman convinces Two-Face that he is the real, original Darknight Detective. Two-Face has been at odds with Gotham's latest district attorney, Kate Spencer, also known as the vigilante Manhunter. Since the arrest of Black Mask, Two-Face has been working at regaining his former power over Gotham. However, his plans have garnered the attention of the FBI. After he discovers a mole in his midst, he flees only to be stabbed by his own henchmen. Two-Face is left for dead, his body dumped off a bridge. Sometime later, two fishermen in the middle of a lake reel in Two-Face's water-logged body.