Legion was introduced in the 1990 comic mini-series Green Lantern: Emerald Dawn, which covers the early days of Hal Jordan's career as the Silver Age Green Lantern. In ancient times, the Green Lantern Corps came across the planet Tchk-Tchk in Space Sector 407, which was home to an aggressive, insectile race. After conquering their own planet, they began to spread to the rest of the galaxy, at which point the Guardians of the Universe decided to take action, sending the Green Lanterns to beat back the Tchk-Tchk and seal off their planet.