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.
Win Mortimer
Mortimer began working for DC Comics in 1945, and quickly became a cover artist for comics featuring Superman, Superboy and Batman. His first known comics work is as the penciler and inker of the 12-page lead Batman story, "The Batman Goes Broke" by writer Don Cameron, in "Detective Comics" #105 (Nov. 1945); contractually credited to Bob Kane, it is also signed "Mortimer." The introduction of Batman's Batboat in "Detective Comics" #110 (April 1946) was another Cameron/Mortimer collaboration. Mortimer launched a Robin feature in "Star-Spangled Comics" #65 (Feb. 1947).