Batman

Batman is a crimefighter operating in Gotham City, he serves as its protector, using the symbol of a bat to strike fear into the hearts of criminals. Unlike other superheroes, Batman is often depicted to lack any "superpowers", instead using lifelong training and equipment to fight crime. His secret identity is Bruce Wayne, a rich playboy and philanthropist who swore to fight crime after witnessing his parents' brutal murder. He has served as a member of various teams, including the Justice League, the Justice Society of America, and the Outsiders. Batman is also the founder and leader of various teams, including the Bat-Family, Batmen of All Nations and Batman Incorporated. He also goes by numerous nicknames, including "The Dark Knight", "the Caped Crusader", "World's Greatest Detective" and the "Defender of Gotham".

Bruce Wayne is born to Dr. Thomas Wayne and his wife Martha Kane, two very wealthy and charitable socialites from Gotham City. Bruce was brought up in the wealthy splendor of Wayne Manor and leads a happy and privileged existence until roughly the age of eight. While returning home one night, his parents were killed by a small-time criminal named Joe Chill. After the incident, Bruce swears an oath to rid the city of the evil that had taken his parents' lives. As he grows up, Bruce engages in intense intellectual and physical training. He also travels abroad, training in various martial arts, fields of science, criminology, and detective skills. After returning to Gotham, Bruce realizes that these skills alone would not be enough. "Criminals are a superstitious and cowardly lot", Wayne remarks, "so my disguise must be able to strike terror into their hearts. I must be a creature of the night, black, terrible..." As if responding to his desires, a bat suddenly flies through the window, inspiring Bruce to assume the persona of Batman.

In the early strips, Batman's career as a vigilante initially earns him the ire of the police. He initially operates alone, using only street contacts and circumstantial allies in his investigations. Batman also comes into conflict with various criminals, including a mad scientist Doctor Death, a vampire called the Monk, and a criminal mastermind Professor Hugo Strange. During this period Wayne was engaged to actress Julie Madison, though this is called off after several encounters with the serial killer Clayface. After witnessing the murders of circus acrobats called the Flying Graysons, Wayne takes in the couple's son Dick Grayson. The boy quickly joined him in his crusade as his sidekick Robin to help capture the criminal responsible for his parents' murder. Shortly afterward, Batman comes into contact with costumed criminals like Joker and Catwoman, who begin taking over the criminal underworld in Gotham. Batman also becomes a founding member of the Justice Society of America, although he, like Superman, is an honorary member and thus only participates occasionally. Batman's relationship with the law thaws quickly, and he is made an honorary member of the Gotham City Police Department by its commissioner, James Gordon. During this time, butler Alfred Pennyworth arrives at Wayne Manor and after deducing the Dynamic Duo's secret identities joins their service.

Batman, in most of his incarnations, is a dark and brooding hero with a personal vendetta against crime and injustice. Psychologically traumatized by the death of his parents, Batman has sworn to rid Gotham from the criminal elements that took his parents away from him. He is extremely pessimistic and suspicious, which often makes it difficult for him to trust people other than Alfred, Commissioner Gordon, Lucius Fox, the Robins, or the Batgirls. Despite this, Batman has proved to have a great love for humanity, which was instilled by his parents. His father was a doctor, while his mother was a crusader against child abuse. Indeed, Batman's oath of vengeance is tempered with the greater ideal of justice. He refrains from killing, as he feels this would not make him any better than the criminals he fights. He is also a very prominent member of the Justice League and the founder of the Outsiders. To protect his secret identity, Batman has constructed a fake persona he can use in his civilian identity. To the world at large, Bruce Wayne is a self-absorbed, irresponsible playboy and philanthropist. Only his closest allies know that this attitude is just an act. It's implied that he also considers Batman his true identity and that his civilian identity was essentially an alter ego as a result of having to watch his parents be gunned down.