This Datacron unlocks the codex entry - Galactic History 66: The Jedi Covenant
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 fall of Exar Kun and the destruction caused by the Great Sith War weighed heavily on the consciences of many Jedi. The Jedi seer Krynda Draay, who had lost her husband in the conflict, blamed herself for not foreseeing Exar Kun's corruption as a Sith Lord and decided to take action. Having trained the order's visionaries for years, she secretly created a Jedi Covenant without the Council's knowledge, binding the most powerful Jedi seers into a WatchCircle.
The Covenant's task was simple: Watch for Sith influences and eliminate them before they became a threat. Funded by Krynda Draay's vast family wealth, the Covenant quietly recruited Jedi--usually those believed missing in action--as its shadows and operatives and sought out Sith artifacts to destroy. Meanwhile, its seers remained vigilant, watching through the Force for any approaching evil.
The first thing needed to retrieve this Datacron is a Hydro-Thinner which can be purchased from the Aurek Base Cantina vendor (Republic) or Dorn Base Cantina Vendor (Empire). The Hydro-Thinner costs 18k credits. Once you have it you'll want to go to the Datacron which is located in Highmount Ridge (Screenshots 1 & 2). Use the Hydro-Thinner on it and collect your reward.