The belief in Hades went back to those primitive ages when the Sumerians of Eridu conceived of the earth as floating on the deep, which surrounded it as a snake with its coils, while the sky covered it above like an extinguisher, and was supported on the peak of "the mountain of the world," where the gods had their abode. This primitive cosmological conception underwent changes in the course of time, but the underlying idea of an abyss of waters out of which all things were shaped remained to the end. The Chaldæan Epic of the Creation declares that "in the beginning," "the chaos of the deep" had been the "mother" of both heaven and earth, out of whom first came the primæval deities Lakhmu and Lakhamu, and then An-sar and Ki-sar, the upper and lower firmament. Long ages had to elapse before the Trinity of the later theology--Anu, Ea, and Bel--were born of these, and all things made ready for the genesis of the present world. Merodach, the champion of the gods of light and law, had first to do battle with Tiamat, "the dragon" of "the deep," and her allies of darkness and disorder. He had proved his powers by creating and annihilating by means of his "word" alone, and the conflict which he waged ended in the destruction of the enemy. The body of Tiamat was torn asunder and transformed into the heaven and earth, her springs of water were placed under control, and the forces of anarchy and chaos were banished from the universe. Then followed the creation of the existing order of things. The sun and moon and stars were fixed in their places, and laws given to them which they should never transgress, plants and animals were created, and finally man.