Mnemosyne — Classical Greek Myth Library

Earth (Gaia), angered at the Titans’ fate, bore the Giants—vast sons with serpents for legs below, in the usual description—and they assaulted heaven. An oracle told the gods that the Giants could not be destroyed unless a mortal fought beside the immortals. Zeus forbade Helios, Selene, and Eos to shine, so that the herbs of invulnerability Gaia sought for her children could not be found; Athena summoned Heracles as the required mortal ally. In the battle on the plain of Phlegra (or Pallene in Thrace/Chalcidice, according to the localization), Heracles’ bow and club finished what the gods began. Apollodorus names the pairings: Heracles shoots Alcyoneus—who could not die while he touched his native land—and, on Athena’s advice, drags the giant from Pallene so that the death takes hold; he shoots Porphyrion after Zeus’s thunderbolt lays the giant low in mid-assault on Hera; and he joins the other Olympians in felling Ephialtes, Eurytus, Clytius, Mimas, Enceladus, Polybotes, Hippolytus, Agrius, Thoas, and the rest, each god matching a named opponent while Heracles’ arrows supply the mortal stroke the oracle demanded. Victory left the cosmic order confirmed and Heracles marked as the gods’ chosen human champion—the same role that culminates, after his own pyre, in Olympian adoption and marriage to Hebe.