Ouranos.
Ouranos, also known as Uranus, Father Sky or Caelus, was the Greek Primordial personifying the sky, the husband of Gaia and the grandfather of the gods.
Overview
In Ancient Greek literature, according to Hesiod in his Theogony, Ouranos was the son and husband of Gaia, Mother Earth. Ouranos and Gaia were ancestors to most of the Greek gods, but no cult addressed directly to Ouranos survived into classical times. Nonetheless, Ouranos is the catalyst that sets off a series of events regarding a son usurping a father in order to claim dominion over the cosmos
History
Theogony
In the Olympian creation myth, Ouranos came every night to cover the earth and mate with Gaia, producing some of the most powerful offspring of any union between primordials. Hesiod named their first six sons and six daughters the Titans, the three one-hundred-armed giants the Hekatonkheir, and the one-eyed giants the Cyclopes.
Children of Ouranos
But despite the boundless potential within each of his offspring, Ouranos hated the children that Gaia bore him. Ouranos imprisoned Gaia's youngest children in Tartarus, deep within Earth, where they caused great pain to their mother Gaia. In retribution, she shaped a great flint-bladed sickle and pleaded with her sons for them to castrate Ouranos. Only Cronus, youngest and most ambitious of the Titans, was willing: he ambushed his father and castrated him, casting the severed testicles into the sea. For this fearful deed, Ouranos called his sons Titanes Theoi, or "Straining Gods."From the blood that spilled from Ouranos onto the Earth came forth the Gigantes, the Erinyes (the avenging Furies), the Meliae (the ash-tree nymphs), and, according to some, the Telchines.
Usurped by Cronus
In some versions of the myth it is Hyperion, along with Cronus, Iapetus, Krios, and Koios who together revolt against their father. When Ouranos descended to the Earth to lay with Gaia, Hyperion along with Krios, Iapetos and Koios waited at the corners of the world and grabbed him as he came down. Kronos then was able to castrate his father with a sickle made by their mother.
After Ouranos was deposed, Cronus re-imprisoned the Hekatonkheires and Cyclopes in Tartarus. Ouranos and Gaia then prophesied that Cronus in turn was destined to be overthrown by his own son, and so the Titan attempted to avoid this fate by devouring his young. Zeus, through deception by his mother Rhea, avoided this fate. After the Titanomachy, Zeus punished the Titan Atlas by having hold up the heavens, which was in this case Ouranos, to forever separate him from Gaia in the hopes of the latter to never mate with Ouranos and attempt to produce children mighty enough to usurp the Olympians.