Growing up in a lower-class family, Harvey was raised with an instinctive dislike and mistrust for the upper-class. These harsh surroundings resulted in him developing repressed mental-illnesses such as bipolar disorder and schizophrenia. His hard work ethic, however, allowed him to rise up to become Gotham’s DA. He was dedicated to his job of upholding law and order, and became one of Batman’s first supporters. At the time of his job, the worst criminal threat was Sal Maroni. He forged a triumvirate with Batman and Commissioner Gordon to bring the man down within the law. The alliance ended tragically when Maroni, believing Dent was responsible for the his father’s death, threw acid in his face; Dent was horribly scarred on the left side of his face and his left hand and he descended into madness. He became obsessed with duality and developed a second persona, the villainous Two-Face. 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 different materials. At all times, he carries a double-sided coin with one side scarred, which he constantly flips to make decisions.
I Believe in Harvey Dent, by Jean-François Brazeau.