What is Crisis on Infinite Earths?
Once upon a time, there was the Justice Society of America, and it was good. Then people got bored by the JSA, and the book stopped. Then, in the 50s, the Green Lantern and Flash were re-imagined and started over with no indication that there had been a previous GL and Flash. And the new heroes formed the Justice League of America, which was also good. The new Flash accidentally traveled to a parallel Earth and met the original Flash, which reignited interest in the JSA. DC declared that the JLA lived on Earth-1, and the JSA on Earth-2. The teams frequently crossed over, and nobody was terribly bothered by the whole parallel universe thing, because it wasn’t hard to understand. DC, flush with money, started buying up smaller comic publishers and adding their characters to the DC multiverse. Every time they bought a new company, that company’s characters got their own parallel Earth. Soon, there were over half a dozen parallel universes, and they didn’t even follow the numbering scheme.
