The Spheres of Influence were the twelve domains of politics and power in the reconstituted Sith Empire. Each of the twelve Spheres, also known as Pyramids, was headed by a member of the Dark Council, and between them they encompassed the entire Empire. Through the Spheres, the Dark Council controlled and oversaw the day-to-day operations of the Empire, and every individual and organization within the Empire ultimately answered to at least one of the Councilors through the hierarchy of the Spheres.
In 4980 BBY, the Sith Emperor reestablished the Sith Empire on the planetDromund Kaas, where they would be safe from the Galactic Republic. Not long afterwards, the Emperor created the Dark Council, a group of twelve Dark Lords of the Sith who would handle the day-to-day running of the Empire as the Emperor gradually retreated into seclusion. Each Dark Councilor took an aspect of the Empire as their own to rule, ranging from joint control of the Imperial Military to the judicial regulation of Imperial society to the ensuring that the Sith Order remained loyal to Sith philosophy. Every Councilor’s successor assumed control of their respective Sphere of Influence, and every organization, group, and individual within the Empire—whether they were Sith or not—ultimately answered to one or more Dark Council member. The Spheres occasionally overlapped, causing conflict between the various Council members, but overall each Council member was responsible for overseeing their own Sphere and dealing with any problems that arose.