Cosmology
From Tolkien Gateway
The structure of the universe, its creation, and divinities. For Tolkien, this would be Eä, and within it Arda (our world in a much earlier age). Within Arda ia included geography and such physical features as the layers of the atmosphere. The account of the creation of Eä and Arda is provided in the Ainulindale. Divinities local to Arda are the Ainur, who govern the world under Eru's mandate.
