The Mezlag sector was a major power in its niche of space in the Unknown Regions, the home of the Mezlagob system and the eponymous Tetrarchy of Mezlagob. It included all four of the founding worlds of the Tetrachy (Mezlagob, Ommol, Hudrel, and Telacia), as well as roughly two dozen of its other worlds. The Keblygrin Way passed through the Mezlag sector, as did the Liberators' Run. The Mezlag sector remained relatively insulated from the Empire's wars until the Nightmare War, when Dolomir fell to the Reawakened and their army of Skavik.