The Theogony details the genealogy of ancient Greek gods, from the beginning of the universe through the Olympian gods and various monsters and heroes descended from them. The poem begins with an invocation to the Muses typical of epic poetry, but with a twist: Hesiod claims that the Muses themselves once descended to visit him and taught him “fine singing.” Hesiod then describes the origins of the Muses and describes their benefits to men who gain their favor, including good judgment, beautiful speech, and reverence from peers.
The poem goes on to describe the beginning of the universe: Chasm and Earth come into being, followed by Tartara and Eros. Eros is to act as the implicit guiding force behind much of the rest of the poem, which focuses on successive generations of gods and goddesses being conceived and born.
Heaven is born from Earth, and many more divine beings are born from their union, including their son Kronos. Heaven, wary of the threat his new children might pose against his dominance, locks them with their mother Earth in a cave, visiting only at night when he is “desirous of love.” Earth and Kronos soon hatch a plan to overthrow cruel Heaven, and Earth crafts an adamantine sickle (a curved, sword-like weapon) with which to do the job. Next time Heaven visits, Kronos ambushes him and castrates him with the sickle, effectively ending his reign over the gods and assuming the role of king of the gods in his stead.
The genealogy of gods continues, charting the births of numerous gods and goddesses, nymphs, heroes, and monsters. Hesiod also includes various myths such as that of Medusa and Heracles, as well as a lengthy description of Hecate, who is especially involved in human affairs and generous toward her worshippers.
The poem then returns to succession, detailing the children born to Kronos and Rhea. Wary of the fate of his father, Kronos swallows each of these children back into himself once they are born, having learned from Earth and Heaven that he would one day be defeated by his own child. Rhea, however, bore Zeus in secret and gave him to Earth to raise, while tricking Kronos into swallowing a disguised stone in Zeus’ place. Once he matured, Zeus, too, tricked his father, forcing Kronos to spit back up all of the children—Zeus’ siblings—that he had swallowed.
The poem then details another episode of trickery, as Prometheus attempts to trick Zeus into taking a smaller cut of meat after a sacrifice. Prometheus also steals fire for humans, prompting additional rage from Zeus. Hesiod details that Prometheus’ punishment is to be chained up, his liver eaten by eagles, for eternity, while humankind’s punishment takes the form of a woman, Pandora, and her box of evils, as well as the female race more generally, whom Hesiod describes as “a great affliction.”
Zeus and the other Olympians then wage war against Kronos and the Titans, with the help of other gods and goddesses whom Kronos had spurned, including Obriareos, Kottos, and Gyges. They triumph over the Titans, and Zeus locks them away in Tartarus so that they cannot escape to cause further conflict.
Hesiod goes on to describe the origins of a variety of other deities, monsters, and heroes related to or otherwise descended from the Olympians. Earth then bears a new rival to Zeus’ power, Typhoeus, whose father was Tartarus. Threatened by his power, Zeus does battle with him, eventually obliterating him entirely.
Zeus has other children, as well. When his first wife, Metis, is pregnant with Athena, Zeus swallows her, fearing a child who might overtake him, and gives birth to Athena out of his head instead. The poem ends by detailing the genealogies of various other mythological characters, including notable mythological figures who have both human and divine parents.