[Source] The Holocron of King Nakgru, also known as the Nakgru Holocron was a Sith holocron. The holocron eventually came be be placed inside the Sanctum of Sakkra-Kla, a sacred Sith tomb that was located on the planet Korriban, where it lay undisturbed for over ten thousand years. In about 6900 BBY, the Sith Lord Sorzus Syn penetrated the Sanctum of Sakkra-Kla and discovered the Nakgru Holocron. She subsequently studied the device and learned from it the history of the Sith Purebloods.