Son and husband

Uranus (Sky) is first of all the son of Gaia (Earth), but secondly he is also her husband. And having wedded his mother, Uranus had by her an impressive offspring:

HECATONCHEIRES

First the HECATONCHEIRES, who were of great size and might, each of them having a hundred hands and fifty heads. Uranus hated this terrible offspring, and used to hide them away in a secret place of earth as soon as each was born. It has been asserted that, in addition, Uranus rejoiced in his evil doing.

CYCLOPES

Thereafter Gaia gave birth to the CYCLOPES, who are known for having one eye on their foreheads. Though they were strong like gods, Uranus, repeating his previous deed, bound them and cast them into Tartarus, a gloomy place in the Underworld, as far distant from earth as earth is distant from heaven.

The Takeover

Then Uranus had more children by Gaia: the TITANS. But Gaia, who had never accepted the fate of her former children, persuaded the TITANS to attack their father, and for that purpose she armed Cronos with an adamantine sickle. And when the opportunity came, all TITANS except Oceanus attacked him, and Cronos cut off his father's genitals, throwing them into the sea behind his back, some say at Cape Drepanum in Achaea.

From the drops of Uranus' flowing blood which fell upon earth, the ERINYES were born, and the GIANTS, and those NYMPHS called MELIADS. The genitals that Cronos threw away were first swept away over the sea a long time, but finally, from the white foam which spread around them, Aphrodite was born.

Regime changes but opression remains

Having dethroned their father, the TITANS brought up their brethren from Tartarus, and gave the rule to Cronos, who wedded his sister Rhea ₁. However, once in power, Cronos bound the CYCLOPES and the HECATONCHEIRES, and shut them up in Tartarus again.
What happened hereafter is told in Titanomachy.

(For Tartarus see Underworld.)