"Detective Comics" #27, debuting in May 1939, featured the first appearance of Batman: a driven millionaire prompted by the murder of his parents to battle crime wherever it appeared. The character proved so popular that he received a comic of his own in 1940. The early years of the comic reflected a bleak, noir-like sensibility, with Batman terrorizing and even killing the criminals he hunted.
Public concern about the content of comic books led to a softening of Batman's image in the 1950s and 1960s. His adventures often featured outlandish elements like robots and space aliens, and he took on a jolly, father-like demeanor.
Sales of Batman comics dipped in the 1960s and the publisher talked about stopping the character forever. Editor Julius Schwartz made dramatic changes in an effort to make the character more contemporary. The newer, campier Batman comics received a boost in sales from a phenomenally popular "Batman" TV show starring Adam West, which debuted in 1966.
In the 1970s, the Batman comics returned to their darker roots. Under writer Denny O'Neill, Batman became a grim, obsessive vigilante again, and the comics stories reflected a bleaker, grittier tone.
Batman comics underwent another major resurgence in the 1980s, with a fresh array of talent creating groundbreaking stories. Frank Miller's "The Dark Knight Returns" posited an aging, near-psychotic Batman waging war against crime in a near-future, while Alan Moore's "The Killing Joke" featured Batman's nemesis the Joker crippling and psychologically tormenting some of Batman's closest allies. In 1988, the comic line killed off Batman's partner Robin after a hotly contested phone-in poll from the fans. Batman comics remained popular in this era thanks in part to the success of a series of feature films.
Batman's appeal has continued into the 21st century, boosted by two blockbuster movies (2005's "Batman Begins" and 2008's "The Dark Knight") which reinvented the popular notion of the character. As of 2010, 10 separate comic book lines cover the adventures of Batman and his associates.