Who is the Greek primordial god of the sky?

The Greek primordial god of the sky was Uranus, also spelled Ouranos. In Hesiod’s creation genealogy, Uranus emerged as the personification of the heavens and became the consort of Gaia, the Earth. Together they produced the Titans, Cyclopes, and Hecatoncheires, making Uranus an ancestor of the later Olympian gods.

Uranus is less a human-shaped sky ruler than the sky itself: an immense heavenly realm arching over Earth. His myth centers on fear of his children. He confined some of them, prompting Gaia to encourage their son Cronus to overthrow him with a sickle. After Uranus was mutilated, the Titans gained power, beginning the succession of divine generations that eventually led to Zeus.

He is often confused with Zeus because Zeus ruled the heavens in the later Olympian order. Uranus belongs to a much earlier generation. He also differs from Aether, who represented the bright upper air, and from Pontus, who personified the sea. The Roman equivalent of Uranus was Caelus.