Ouranos was the first ruler of the universe, created by Gaea when she emerged from Chaos. Ouranos, with Gaea, became the father of the Titans, the Cyclopes and the Hecatoncheires (hundred-handed ones).
Ouranos was afraid that some of his children would rebel against him, so he imprisoned them within Gaea's earth womb. Kronos, the youngest of the Titans, freed his siblings by castrating his father. Ouranos' blood gave birth to the Furies, and Aphrodite was born of the discarded member when it fell into the foaming sea.