“Storm god of the air. Enlil was born of the union of An (heaven) and Ki (earth), who were regarded as joined together. Enlil separated them—the element air may have been thought to separate the vault of heaven from earth by its own expansion. Enlil married Ninlil, who bore him three gods of the underworld (Nengal, Ninazu, and an unknown god) and Nanna, the moon, who in turn became the father of Utu, the sun. Next, Enlil impregnated his mother Ki and produced Nintu, another earth goddess. Enlil became more important in the pantheon than his father An, and in turn he was himself to a degree supplanted from his place as principal god by Enki. Enlil was the chief god of the Sumerian city of Nippur. In the Babylonian period, Marduk took on many of his attributes, and Akad became a storm god.”
Excerpted from: Murphy, Bruce, ed. Benet’s Reader’s Encyclopedia, Fourth Edition. New York: Harper Collins, 1996.