The One Sith was founded on the planet Korriban, which was the original homeworld of the Sith species. In other words, just as Yoda was able to hide himself on Dagobah, the overwhelming dark side ...

The first "true" Sith was a species of red humanoid aliens who were later conquered by exiled Dark Jedi around 7,000 years before A New Hope. The Dark Jedi then appropriated their name to become ...