The History of the Asgard (Stargate SG1)

The Asgard were a highly developed, philanthropic race in the Ida Galaxy which visited and protected humans on Earth and elsewhere. When interacting with early humans, they posed as beneficent protective gods, eventually giving rise to the Norse mythology on Earth. Part of the Alliance of Four Great Races, they were among the most advanced races in the universe, matched only by the Ancients, the Nox, and possibly the Furlings. They assumed the role of protectors of the Milky Way galaxy and later passed that role down to the Tau’ri, to whom they gifted all of their knowledge to. info from: