The Dark Knight and the Boy Wonder. The Dynamic Duo. What more can be said? Perhaps the most familiar of all superhero teams, and the prototype for scores that followed.. According to Wikipedia:
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"In his secret identity, Batman is Bruce Wayne, a wealthy businessman who lives in Gotham City. To the world at large, Bruce Wayne is often seen as an irresponsible, superficial playboy who lives off his family's personal fortune (amassed when Bruce's family invested in Gotham real estate before the city was a bustling metropolis) and the profits of Wayne Enterprises, a major private technology firm that he inherits. However, Wayne is also known for his contributions to charity, notably through his Wayne Foundation. Bruce creates the playboy public persona to aid in throwing off suspicion of his secret identity, often acting dim-witted and self-absorbed to further the act.

The first Batman story, "The Case of the Chemical Syndicate," was published in Detective Comics #27 (May 1939). Bill Finger said, "Batman was originally written in the style of the pulps," and this influence was evident with Batman showing little remorse over killing or maiming criminals. Batman proved a hit character, and he received his own solo title in 1940, while continuing to star in Detective Comics. By that time, National was the top-selling and most influential publisher in the industry; Batman and the company's other major hero, Superman, were the cornerstones of the company's success.

The early, pulp-inflected portrayal of Batman started to soften in Detective Comics #38 (April 1940) with the introduction of Robin, Batman's kid sidekick. Robin was introduced, based on Finger's suggestion Batman needed a "Watson" with whom Batman could talk. Sales nearly doubled, despite Bob Kane's preference for a solo Batman, and it sparked a proliferation of "kid sidekicks." The first issue of the solo spin-off series Batman was notable not only for introducing two of his most persistent antagonists, the Joker and Catwoman."
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