Batman
The first Batman story, "The Case of the Chemical Syndicate", was published in "Detective Comics" #27 (May 1939). 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, Detective Comics 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 two characters were featured side-by-side as the stars of "World's Finest Comics", which was originally titled "World's Best Comics" when it debuted in fall 1940. Creators including Jerry Robinson and Dick Sprang also worked on the strips during this period.
Detective Comics
Batwoman first appeared in "Detective Comics" #233 (July 1956) Since the family formula had proven very successful for the Superman franchise, editor Jack Schiff suggested to Batman co-creator Bob Kane that he create one for the Batman. A female was chosen first, to offset the charges made by Fredric Wertham that Batman and Robin were homosexual. Writer Bill Finger and artist Sheldon Moldoff introduced Bat-Mite in issue #267 (May 1959) and Clayface in #298 (Dec. 1961).