The Codex Aeternum

Commissioned by King Reyumi I after the War of Darkness to ensure that magic would never again run unchecked. He gathered the greatest minds of the age — archmagi, druids, priests, and scholars — and had them debate and refine the first unified laws of magic.
  Written on indestructible vellum laced with silver thread, bound in stone-etched plates taken from the Salathar Mountain Range, said to be infused with divine blessing. The book itself is kept in the King’s Artifact Room in Ferinfall, under permanent guard.
  The Codex Aeternum is not static. Whenever a magical breakthrough occurs that redefines understanding, the King’s appointed council petitions to have the Codex updated. This act is ceremonial and requires the King’s seal.