The Celestial Realm was once the home of the Keeper, the one god of the Arcverse whose power ordered the Five Dimensions. The Keeper died three centuries ago in a catastrophic event known as the Sundering, and his collapse led to devastation across Celestium. The paradise of the Keeper's order gave way to a chaotic new reality where the energy of the great orb at the centre of the dimension, the Light of the Keeper, began to ebb away. Over the past few millennia, mortal fiefdoms have established themselves in the Celestial Realm, but at the centre of Celestium are the islands that were once home to the Keeper's most loyal servants, the Athervannir.