The Great Library
All wizards and sorcerers are born with an innate talent that allows them to focus and control magic in ways that a vast majority of mortals cannot, because of this they are potentially the most dangerous creatures on earth. A druid maintains the balance of nature, a cleric must follow the commandments of their god, but practitioners of the arcane have no loyalty or code that restricts when and upon whom they may use their powers. The great library serves as an artificial restriction by providing training with, and policing the use of arcane magic.
Any child with any magical talent is required to be tested by the Library. Should they prove powerful enough they are taken from their parents and raised in an educational environment designed to facilitate learning and self-control. A majority of mages manage to graduate from their apprenticeship in five to ten years, any who do not prove themselves capable of controlling their abilities have their powers sealed by the masters of the library. Those who have finished their training are still required to follow the rules of The Great Library or they will be hunted down by the Ouroboros.
The Library itself exists outside of the mortal world in its own pocket dimension accessible only by arcane practitioners at specially designed gates (although more powerful arcanists can access it simply by using enough power).
The governing body of The Library is known as The Council of Lore and is composed of the seven most senior wizards in the library.