The DC Comics Universe was a mess. For years DC writers and artists had thrown continuity out the
window. To make matters worse during
the Silver Age the concept of alternate universes and Earths was used to maximum
effect.
So many Supermen, Wonder Women, Batmen and other DC heroes
and villains existed readers needed a score card just to keep track.
Meanwhile Marvel Comics', DC's chief competitor, sales
numbers continued to increase. While
DC's Universe lacked consistency and continuity, Marvel thrived on the fact
that it had both.
Something had to be done.
Writer Marv Wolfman (along with penciller George Perez)
pitched the idea of a massive event that would 'clean the slate' of the DC Universe
and kick-start it with a whole new beginning.
DC execs agreed and in 1985 DC Comics' Crisis On Infinite
Earth maxi-series was launched.
The series found the entire DC Universe in a state of
flux. Entire alternate Earths and
universes were destroyed by a devastating ant-force. Billions died, including many of DC's alternate heroes and
villains.
The series tied into all of DC's titles and as Crisis
progressed changes swept the DC Universe.
The first issue set up the 'Crisis' and introduced several
key players: most notably the Monitor, Pariah, Harbinger and a mysterious dark
force.
Later key DC heroes would die: the Flash and Supergirl among
them.
Once finished the series would alter and condense the DC
Universe into a manageable cohesive entity.