Forseti was a Goa'uld who, long ago, enslaved the Viking people on Earth. He was cast out of his position of power by Odin, though he managed to live and indeed thrive. Thor later tried to defeat him, but even he was unable to do so. Legend persists that Forseti was still alive when the Goa'uld left Earth. (SG1: "The DVD Collection 10")
Forseti is the Norse god of justice, an ironic choice for a Goa'uld.
- Forseti on the Wikipedia