<Tr> <Th_colspan="2"> Collected editions </Th> </Tr> <Tr> <Th> Dark Knight Archive Volume 1 </Th> <Td> ISBN 1 - 56389 - 050 - X </Td> </Tr> <P> Batman is an ongoing American comic book series featuring the DC Comics superhero Batman as its main protagonist . The character first appeared in Detective Comics #27 (cover dated May 1939). Batman proved to be so popular that a self - titled ongoing comic book series began publication with a cover date of Spring 1940 . It was first advertised in early April 1940, one month after the first appearance of his new sidekick, Robin, the Boy Wonder . </P> <P> Though the Batman comic book was initially launched as a quarterly publication, it later became a bimonthly series through the late 1950s, after which it became a monthly publication and has remained so since . In September 2011, The New 52 rebooted DC's continuity . In this new timeline, the original Batman series ended and was relaunched with a new first issue . </P>

When was the first batman comic book published