Darth Vengean was succeeded as head of the Sphere by Darth Baras during the Cold War. With the death of Baras by the hands of the Emperor's Wrath, Darth Arho inherited the Sphere and was responsible for the assault on Ilum. By 3637 BBY, Darth Arkous held the position on the Council, but was secretly a Revanite. His machinations culminated in the assault on Tython before being defeated on Rakata Prime in the campaign against the Revanites.
After the Empire's defeat at the hand of the Eternal Empire, the sphere was combined with the Spheres of Defense of the Empire and Military Strategy into the Sphere of Military Command by Empress Darth Acina.
- Star Wars: The Old Republic Encyclopedia