Nyx

In Greek mythology, Nyx (Greek: Νυξ, "night") was the primordial goddess of the night. She was sometimes depicted with an aureole of darkness above her head and as a winged goddess or a charioteer. In Roman mythology, Nyx is closely equated with Nox.

Family
According to Hesiod, she was the child of Chaos and the wife of her brother, Erebus. With Erebus, she mothered Aether and Hemera, and she mothered several deities without a father, including: Moros, the Keres, Thanatos, Hypnos, the Oneiroi, Momos, Oizys, the Hesperides, the Moirai, Nemesis, Apate, Philotes, Geras, and Eris.

Sophrosyne, Epiphron, Hybris, and Eleos are typically said to be children of Erebus and Nyx.

Tartarus
While describing Tartarus, Hesiod describes the home of Nyx and her daughter, Hemera. Just as Hemera leaves Tartarus, Nyx is just entering in a cyclical nature. This myth is used to explain the continuing cycle of day and night.

Hypnos and Zeus
In the Iliad, Homer writes about an altercation between Hypnos and Zeus in which Hera asked Hypnos to put Zeus to sleep so she could cause misfortune in Heracles' life. After awakening, Zeus was furious at Hypnos who ran to his mother, Nyx. Zeus, fearing the great power of Nyx, forgave Hypnos and held his anger at bay.