In 1955, DC launched an ongoing series entitled The Brave and the Bold. It originally featured done-in-one stories of varying heroes from issue to issue, and eventually became a vehicle for experimenting with new character ideas through team-ups. Its most notable issue – The Brave and the Bold #28 – brought together, for the first time, the world’s greatest superheroes: the Justice League. The series was quite successful, running for almost three decades and producing 200 issues of odd pairings and crazy adventures.
From my collection: The Brave and the Bold #99 (Nov. 1971), where Batman gets possessed by an evil spirit and the Flash comes in to save the day.