This Datacron unlocks the Codex Entry - Galactic History 56: The Brotherhood of the Sith
This datacron holds unheard of power and knowledge collected by an ancient race. You access its power and discover writings which are clearly only one small piece of a massive galactic history:
The Jedi still hoped to save their fallen brother Ulic Qel-Droma, who had become leader of the evil Krath cult. Ulic's close friend Nomi led a second rescue mission to the city of Cinnagar to bring him home. But again Ulic resisted, unleashing his vast armies until the Jedi were forced to withdraw.
It was then that the Dark Jedi Exar Kun arrived at Cinnagar's royal palace. From Yavin Four, Exar Kun had sensed Ulic's growing dark power and saw him as a threat. The two men clashed in a ferocious duel until the spirit of Marka Ragnos, a long-dead Sith Lord, appeared to them.
Ragnos commanded Ulic Qel-Droma and Exar Kun to join forces; together, they could bring about the long-prophesied Golden Age of the Sith. With Exar Kun as Dark Lord and Ulic as his apprentice, the Brotherhood of the Sith was born.
Coordinates: X - 1018 , Y 22
This Datacron is located inside the Okara Droid Factory in central Balmorra. If you forget where this factory is located refer to (Screenshots 1 & 2). Once inside you will be going to the western most elevator titled "Assembly Line". Take the elevator down and follow the hallways until you reach the giant room in the northeastern most end of the map. This is the Assembly Room, go figure. In here you will want to jump down to the floor below and make your way over to a super secret entrance in a column (Screenshots 3 & 4).
Inside this little room you need to drop down to the different pipes until you can see the Datacron. Once you can see the Datacron you need to fall down to the pipe that it is on (Screenshot 5).