Erebos

Chaos and Nyx grew weary of their power and called their son Erebos to assist them. He rose from the primeval darkness and took the name Darkness. His first act was to overthrow Chaos and take his place. He then sought a companion and married Nyx, his own mother. In that telling, the union was accepted because the first beings had no fixed laws at the beginning of the world.

Erebos became the darkness associated with the Underworld, while Nyx became the darkness that covered the earth. When evening came, Nyx drew Erebos across the sky. He filled every opening and hollow with darkness. At each new day, Erebos's daughters of light scattered him. Nyx and Erebos therefore remained closely linked, but they were not identical. Nyx carried within herself the possibility of day, while Erebos was the complete absence of sunlight.

In another telling, Erebos and Nyx stood together among the first beings to come from Chaos. Chaos came first, followed by Gaia, Tartarus, and Eros, while Erebos and Nyx emerged directly from Chaos. Nyx then conceived Aither and Hemera after joining with Erebos. This telling made Erebos and Nyx siblings rather than mother and son.

The tellings also differed over Erebos's nature. One rejected the idea that he was a path from Hades or a region above Hades. It made him a region of darkness set against the realm of light. Another called him the darkness that shrouded the Underworld. In every telling, Erebos emerged at the beginning of the cosmos as a primeval power of darkness and remained closely joined to Nyx.