Batman: Detective Comics
Detective Comics is a comic book published by DC Comics since 1937. It is, along with Action Comics (the book that launched with the debut of Superman), one of the company's best-known titles - in fact, the "DC" in the company's name comes from "Detective Comics". more...
With more than 800 issues now published, it is the longest continuously-published comic book in the United States, remaining a monthly publication as of 2006. (Action Comics, however, has amassed more individual issues due to the fact that it was published as a weekly for a period in the 1980s, and the record-holder for most issues published is Dell Comics Four Color series, which amassed more than 1,300 issues over a 23-year run.)
Originally an anthology-style comic, featuring stories in the "hard-boiled detective" genre popular at the time, the first issue contained stories featuring the characters of Ching Lung (a Fu Manchu-style Asian villain), Slam Bradley (created by Jerry Siegel and Joe Shuster), and Speed Saunders, among others.
However, the fame of Detective Comics was assured by issue #27 (May 1939), which featured the first appearance of Batman (as "The Bat-Man"). He would eventually become the star of the title.
Issue #38 (April 1940) introduced Batman's sidekick (billed as "The Sensational Character Find of 1940" on the cover), Robin. Robin's appearance (and the subsequent increase in sales of the book) soon led to the trend of costumed crimefighters and their young sidekicks that characterize that era.
Read more at Wikipedia.org