Little is known about The Magisterium and even its location is unclear. The best guess seems to be far to south, near an ocean within a city with great buildings shaped like humanoid faces. What little is known has been gleaned second hand from mercantile routes that vanish into the far south and more recently from Magisterium incursions into the North. Magisterium fortresses appear to be able to float and are used to transport Magisterium forces great distances, protected by powerful magics.
What is known is that the Magisterium appear to have very powerful magics at their disposal and numerous mages to put them to work. In particular, they have mastered the art of teleportation allowing them to strike without warning into even the most heavily guarded location. Magisterium sorcerers can be identified by their crimson robes and a golden disk upon their brow that bears the mark of a six pointed sun-burst with an eye at its centre. The Magisterium appears to treat all those unable to manipulate magic with utter contempt, barely willing to engage them in conversation.
Although few know it the Magisterium appears to be ruled by a Dragonborn sorcerer of immense power, inhabitants of the Magisterium refer to it only as the Demiurge.
The Magisterium has been cast down and now the region is under the control of the nomadic Atlan people.