The Theogony "the genealogy or birth of the gods" is a poem by Hesiod (8th – 7th century BC) describing the origins and genealogies of the Greek gods, composed c. 730–700 BC. It is written in the Epic dialect of Ancient Greek and contains 1022 lines.

Hesiod's Theogony is a large-scale synthesis of a vast variety of local Greek traditions concerning the gods, organized as a narrative that tells how they came to be and how they established permanent control over the cosmos. It is the first known Greek mythical cosmogony. The initial state of the universe is chaos, a dark indefinite void considered a divine primordial condition from which everything else appeared. Theogonies are a part of Greek mythology which embodies the desire to articulate reality as a whole; this universalizing impulse was fundamental for the first later projects of speculative theorizing.

Hesiod appropriates to himself the authority usually reserved to sacred kingship. The poet declares that it is he, where we might have expected some king instead, upon whom the Muses have bestowed the two gifts of a scepter and an authoritative voice (Hesiod, Theogony 30–3), which are the visible signs of kingship. It is not that this gesture is meant to make Hesiod a king. Rather, the point is that the authority of kingship now belongs to the poetic voice, the voice that is declaiming the Theogony.