Codex/Galactic History 79: The Conclave at Katarr

The Galactic History 79: The Conclave at Katarr codex entry is located within the Achievements:Datacrons section of a player's codex once it has been unlocked.

Codex entry
"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:

Dark times had come to the Republic. Reconstruction from the Jedi Civil War was still ongoing, and the Jedi Order’s numbers were dwindling. Worse, many Jedi sensed a new Sith threat emerging but could not pinpoint the source.

Finally, the Jedi Council called a conclave on the Miraluka colony of Katarr. The order’s Masters, including the legendary Vandar Tokare, gathered to discuss the possibility that the Sith had returned. They did not know that Darth Nihilus, a being of pure hunger and dark side power, was approaching the colony.

Drawn to the assembled Masters, Nihilus devoured the life energy of everything on Katarr. Millions of Miraluka died, along with most of the Jedi Order’s senior members. Walking Katarr’s lifeless surface later, Darth Nihilus came across the only survivor: the traumatized Miraluka Visas Marr, whom Nihilus took as his apprentice."