Concordiat Mysterium

The Concordiat Mysterium was a great conclave of powerful arcanists and other (mostly Lawful) powerful entities to establish contract magic as the supreme form of Arcana. It is so named because none know how it was done or if it can be modified, only that the fabric of magic itself was less predictable but more powerful before.
Many of the involved entities were destroyed or subsumed to empower the new paradigm, and it is said that the material world was permanently bent towards a more orderly pattern when it was enacted.