Batman is the secret identity of Bruce Wayne, an American billionaire playboy, industrialist, and philanthropist. Having witnessed the murder of his parents when he was just eight years old, he swore revenge on criminals, an oath tempered with the greater ideal of justice.
Wayne then seeks Ra's al Ghul, Head of the Demon and Master of the League of Assassins. Ra's al Ghul and Bruce Wayne share the same ideals. After a series of tests, Ra's al Ghul agrees to train Bruce both physically and intellectually. Bruce Wayne then betrays the League of Assassins and escapes, thus creating the rivalry between Batman and Ra's al Ghul. Bruce Wayne returns to Gotham and dons a bat-themed costume in order to fight crime.
Batman operates in the fictional Gotham City. His base of operations is famously known as the Batcave. He is assisted by various supporting characters including his crime-fighting partner, Robin, his butler Alfred Pennyworth, the police commissioner Jim Gordon, and occasionally the heroine Batgirl. He fights an assortment of villains, often referred to as the "rogues gallery," which includes the Joker, Harley Quinn, The Penguin, Clayface, The Riddler, Two-Face, Black Mask, Ra's al Ghul, Scarecrow, Poison Ivy, Bane, Catwoman, and Mr. Freeze, among others.
Unlike most superheroes, he does not possess any superpowers; he makes use of intellect, detective skills, science and technology, wealth, physical prowess, martial arts skills, an indomitable will, fear, and intimidation in his continuous war on crime.