Enûma Eliš
In the Babylonian "Enûma Eliš", Marduk assigns the Anunnaki their positions. A late Babylonian version of the epic mentions 600 Anunnaki of the underworld, but only 300 Anunnaki of heaven, indicating the existence of a complex underworld cosmology. In gratitude, the Anunnaki, the "Great Gods", build Esagila, a "splendid" temple dedicated to Marduk, Ea, and Ellil. In the eighth-century BC "Poem of Erra", the Anunnaki are described as the brothers of the god Nergal and are depicted as antagonistic towards humanity.