The Greek cosmogony, or creation story, is rife with familial rivalries over power, some of which resulted in violent acts such as castration, cannibalism, rape and imprisonment. Despite this chaotic beginning, the divine hierarchy remained relatively stable in its the aftermath, partly because Zeus forestalled any challenge to his reign by preventing the birth of a potential successor.

The Castration of Uranus

Uranus, the sky, despised many of the children his wife Gaia, the earth, bore. Unlike the beautiful Titans, the one-eyed Cyclops and many-armed Kottos, Briareos and Gyges were monstrous in form and in nature. Uranus secreted these children into the prison of Tartarus, enraging the maternal Gaia. She colluded with her son, the Titan Cronus, to depose Uranus. She fashioned a serrated sickle from a mythic metal called "adamant," which Cronus used to sever the genitals of his father.

Cronus Cannibalizes His Children

Uranus promised retribution for his son's unforgivable act, and Cronus grew paranoid that he, too, would be supplanted by his child. Though his wife Rhea bore many children, Cronus refused to allow them to grow large enough to defeat him in combat. Instead, he devoured his children as soon as they were born, imprisoning them in his stomach just as Uranus had imprisoned the children of Gaia. As Cronus had also failed to release his siblings from their prison, both Gaia and Uranus had reason to seek revenge against him. They helped Rhea to save her next child, Zeus, raising the child in secret until he was strong enough to defeat his father.

Liberation and War

When Zeus was grown, he conspired with Metis, daughter of the Ocean, to free his siblings. Metis slipped Cronus a powerful emetic and he immediately disgorged the future Olympian gods, who joined Zeus in a great war against the Titans. The war lasted for 10 years, until Zeus freed the children of Gaia from Tartarus, which tipped the odds in the favor of the Olympians. Armed with lightning and superior weaponry, the Olympic gods vanquished the Titans and imprisoned them in Tartarus.

Destroying the Line of Succession

Though Metis had been integral to the Zeus's victory, he treated her quite poorly in the aftermath of the war. Uninterested in his romantic pursuits, Metis shapeshifted in an attempt to escape him. Zeus eventually overpowered and impregnated her, but her troubles didn't end there. Gaia and Uranus predicted that after giving birth to Zeus's daughter, Metis would bear a son who would supplant Zeus. To prevent this, Zeus devoured Metis to prevent her from conceiving again. Some time later, Zeus suffered from an excruciating headache. His son Hephaestus cleaved his skull open, allowing Athena to escape, fully grown and armed. Thus, Zeus maintained his leadership and Metis remained trapped, unable to fulfill the prophecy.