The Ancients originally existed in another realm, one that is vastly different from our own. This plane of existence was bridged to ours by wormholes. When they became aware of the various species in our realm, and many of those species' aggressive tendencies, they modified several members of their own species, allowing them to live and exist in our universe. These individuals became the Ancients and they were tasked to catalogue, report, and influence the activities of the species in our universe.