If Batman ever had a brother, he would be the pulp hero called
the Black Bat. Both bat-caped heroes debuted in the same year,
1939. It was a strange coincidence. Blame The Shadow for that.
He was in his eighth year fighting crime in the pages of his
celebrated pulp magazine, and Orson Welles was bringing him to
life on radio, when two different publishers decided the time
was perfect to copy The Shadow. Batman was the creation of
artist Bob Kane and writer Bill Finger. Huge fans of The Shadow,
they literally took a random issue of The Shadow Magazine and
adapted it into a six-page comic book story, reimagining The
Shadow as the Batman. He debuted in Detective Comics #27, dated
March, 1939, in "The Case of the Chemical Syndicate," which was
freely adapted from the 1936 Shadow mystery, Partners of Peril.
At virtually the same time, over at the Thrilling Group pulp
house, editor in chief Leo Margulies asked prolific writer
Norman A. Daniels to create a new hero for Black Book Detective
magazine. Daniels came up