The Sphere of Ancient Knowledge, also known as both the Pyramid of Ancient Knowledge and the Ministry of Ancient Knowledge, was one of twelve Spheres of Influence of the Sith Empire. Headed by a Dark Councilor, the Sphere was responsible for the protection and expansion of Sith knowledge.
The Pyramid of Ancient Knowledge was a power base of the Sith Empire responsible for guarding and research of ancient Sith knowledge. As with every other pyramid within the Empire, it was composed of many other power bases of Sith Lords, all vying to increase their own strength and standing amongst the Sith, though whichever power base they served or controlled, ultimately all in the pyramid answered the Dark Councilor at its head.
Between 3642 BBY and 3640 BBY, the pyramid had three successive leaders. After Darth Arctis died in unknown circumstances, he was replaced by Darth Thanaton. But Thanaton's victory was short-lived as he lost his own Kaggath against his rival, Lord Kallig, who defeated him in front of the other members of the Dark Council and was put out of his misery by Darth Mortis, head of the Sphere of Laws and Justice. Upon returning to Dromund Kaas, both Kallig's and Thanaton's allies and servants pledged allegiance to the new Dark Lord of the Sith and Dark Councilor.
Later, on Rishi, Darth Nox's lieutenant, Moff Pyron, briefed Nox on current military movements. He advised that Nox seek out Lord Veijel, who believed he had found the means of granting the Darth eternal life. Though Talos Drellik advised against it, Nox granted Veijel resources to pursue their goal of eternal life.
Following the war against Zakuul, Empress Darth Acina merged the Spheres of Influence into five new spheres, with the Sphere of Ancient Knowledge merging with the Spheres of Mysteries and Sith Philosophy into the Sphere of Sith Doctrine. Following the reform, Darth Anathel led the sphere.
Depending on the player's choices after ascending to the Dark Council, Darth Nox either had the sphere purged of Thanaton's supporters, ordered doubling of efforts to uncover lost Sith rituals and artifacts, or simply declared that the Sphere was to fight the Republic.
If the player spared Harkun and Achelon, they would be present and bow before the Sphere's new leader. If Achelon was killed, Kirnon would take his place.
If Darth Nox kills Darth Anathel and rejoins the Sith Empire, they will be Head of the Sphere of Ancient Knowledge once again, the Sphere now being called Sith Doctrine.
- Star Wars: The Old Republic Encyclopedia