In the Letters of JRR Tolkien, he tells that Manwe was Lord of the Valar, therefore the high or Elder King of Arda. Arda means "realm" and was the name given to our world or earth, as it is "the place, within the immensity of Ea, selected to be the seat and special domain of the King - because of his knowledge that the Children of God would appear there". Eru does not physically inhabit any part of Ea.