Fueled by the base desires and actions of mortals, Chaos seek to dominate the Mortal Realms. They serve the Four Chaos Gods. Before Sigmar's retaliation in the Age of Sigmar, they had conquered seven of the eight Mortal Realms, beginning the Age of Chaos. The phrase "Slaves to Darkness" is used to cover all those who have fallen under the control of, or pledged themselves to, the Forces of the Chaos gods. While the energies of chaos touch all things magical, there are those who fully give themselves to the deities of this realm, and seek to conquer not just the works of the Old Ones, but the very fabric of reality itself.