The Know Man was an immortal being responsible for the genetic spark. Know Man was originally a primitive human (possibly a contemporary of Vandar Adg) who discovered a crashed Controller craft. The Controller in question had been assigned to shore up Earth for the future attack of Mageddon, but he was dying. He altered the primitive man, making him immortal and incredibly intelligent. For thousands of years, the Know Man enhanced himself, developed advanced technology, and attempted to learn the Controller's mission on Earth.
After the Know Man learned about Mageddon, he enacted a plan to save the Earth. Using the powers of Doctor Destiny, he unleashed the genetic spark, stripping heroes of their powers and heroic identities while granting powers to everyone else. He hoped to have a superhuman army ready to battle Mageddon when the time came. However, he also indirectly unleashed chaos across the world, leading the Justice League of America to remember and unite against him. Defeated, his spark undone, the Know Man left the world's protection in the hands of the JLA.