In 1981, Wolfman was editing "Green Lantern". He got a letter from a fan asking why a character did not recognize Green Lantern in a recent issue despite the two having had worked together in an issue three years earlier. Soon afterward, Wolfman pitched "Crisis on Infinite Earths" as "The History of the DC Universe", seeing it as a way to simplify the DCU and attract new readers. "The History of the DC Universe"s title was changed to "Crisis of Infinite Earths" because its premise, involving the destruction of entire worlds, sounded more like a crisis.