Finally, the Mandalorians had been routed. The Jedi generals Revan and Malak had killed Mandalore and hounded the remnants of the enemy fleet far beyond the boundaries of Republic space‒and in so doing, performed terrible deeds and learned dark powers. But there were darker days to come. During Revan's pursuit of the Mandalorians, he and Malak discovered the ancient Sith Empire hidden on Dromund Kaas.
Realizing this Empire was the true threat to the Republic, Revan and Malak faced the Sith Emperor himself, intending to cut off the serpent's head‒but the Emperor was too powerful. Overwhelmed by the Emperor's dark presence, they pledged themselves to his service. The Sith Emperor anointed Revan and Malak as true Sith Lords and sent them to seek out the Star Forge, an ancient alien space station capable of producing powerful starships and droids.
Never revealing the existence of the Emperor, Revan and Malak then returned to the armies that had followed them against the Mandalorians, armed their loyal servants with the Star Forge's weapons, and marched to war against the Republic.