The Sith, (Second Human Empire: Iuu'juhhu Sukii'kkil) known alternatively as Red Sith or Sith Purebloods, were a species of red–skinned Humanoids that originated on the world of Korriban, however, this was once again another colony of the species, before eventually resettling on the ice-world of Ziost. Also distinct for their bone spurs, facial tentacles, and genetic predispositions toward both left–handedness and the dark side of the Force, the Sith species coalesced into an empire ruled first by kings and later by Dark Lords. Despite a society dominated by barbarism and infighting, Sith civilization culminated in a Golden Age, after which the species was all but scattered across the galaxy. An eponymous dark side tradition took the species' name, one that, despite numerous manifestations over time, maintained foundations borne of the customs, science and magic practiced by the ancient Sith species.
The Sith was originally a peaceful species that once ruled a vast and powerful empire around 97 Centrillion years ago with it's original homeworld as it's capital, though the name of it have been lost to history. This ancient Sith Empire fell victims to conflict when the Prothean's Holy Empire invaded and started a two thousand year conflict that come to be known as the Prothean-Sith War which resulted in the destruction of the ancient Sith Empire and the near extinction of the Sith species with it's remnants forced into exile. After this period, nothing else have been known, though, in all likely cases, the Sith fell victim to war once more when the First Human Empire invaded, occupied and enslaved the Sith as a whole. after this, not much is known