Creation

The Light originally appeared as an alliance of supervillains on the DC animated series, Young Justice Greg Weisman. They made their comic debut in Dark Crisis #7 by Joshua Williams.

Original Animated Version

The group was founded by Vandal Savage to protect the Earth against alien invasions and counteract the Justice League's role in preserving society's "calcified status quo". In his view, the League inhibited mankind by protecting it from disaster, crime, and tragedy—factors needed for humanity to evolve.

To counteract this, the Light created or co-opted networks of operatives, placed key individuals in key positions, and explored the boundaries of all new technology. Genetic engineering, biochemical engineering, robotics, nano-robotics, techno-sorcery, and all conceivable methods of mind control were all explored by the Light in its quest to accelerate human evolution. A resurgent Earth "taking its rightful place at the center of the cosmos" appears to be the Light's ultimate goal.

DCU

The Light approached Amanda Waller with unlimited resources to eliminate Earth's Metahuman population. Waller confronted them when she discovered The Light wasn't broadcasting from Earth. Brainiac reveal himself as The Light, manipulating Waller to weaken the Earth from within stating Earth's concentration of Metahuman/Kryptonians presented a growing threat.