According to Hesiod, the Erinyes were born of Gaia (Earth) when she received the blood of Ouranos (Sky):
> And Heaven came, bringing on night and longing for love, and he lay about Earth spreading himself full upon her. Then the son from his ambush stretched forth his left hand and in his right took the great long sickle with jagged teeth, and swiftly lopped off his own father's members and cast them away to fall behind him. And not vainly did they fall from his hand; for all the bloody drops that gushed forth Earth received, and as the seasons moved round she bore the strong Erinyes and the great Giants with gleaming armour, holding long spears in their hands and the Nymphs whom they call Meliae all over the boundless earth.
>
> Source: Hesiod, Theogony