While the undying Emperor serves as the unquestioned leader of the Empire, the twelve members of the Dark Council oversee the daily workings of their vast civilization and speak in the Emperor's name. Each is among the most powerful Sith in the galaxy; to hold a seat on the council is the highest honor and the greatest position of influence a Sith can attain.
The individual members of the Dark Council control their own spheres of influence and pyramids of subordinate Sith‒overall Imperial military strategy falls in the hands of one Dark Council member, while study of ancient artifacts falls into the hands of another. These spheres occasionally overlap, leading to conflict. However, every Sith Lord and apprentice is ultimately answerable to the council member at the top of his or her pyramid. Similarly, non-Sith organizations are usually clearly answerable to one Dark Council member or another.
Meetings of the Dark Council are normally held in the Citadel on Dromund Kaas or in the Sith Academy on Korriban. It's rare for all members to gather at once‒power plays among members are frequent, and several of the Dark Lords are virtual hermits. On the occasions when the Emperor summons them, however, all members of the Dark Council are expected to gather and obey.