GERYON (Geryones, Geryoneus), in Greek mythology, the son of Chrysaor and Callirrhoë, daughter of Oceanus, and king of the island of Erytheia. He is represented as a monster with three heads or three bodies (triformis, trigeminus), sometimes with wings, and as the owner of herds of red cattle, which were tended by the giant shepherd Eurytion and the two-headed dog Orthrus. To carry off these cattle to Greece was one of the twelve “labours” imposed by Eurystheus upon Heracles. In order to get possession of them, Heracles travelled through Europe and Libya, set up the two pillars in the Straits of Gibraltar to show the extent of his journey, and reached the great river Oceanus. Having crossed Oceanus and landed on the island, Heracles slew Orthrus together with Eurytion, who in vain strove to defend him, and drove off the cattle. Geryon started in pursuit, but fell a victim to the arrows of Heracles, who, after various adventures, succeeded in getting the cattle safe to Greece, where they were offered in sacrifice to Hera by Eurystheus. The geographical position of Erytheia is unknown, but all ancient authorities agree that it was in the far west. The name itself (= red) and the colour of the cattle suggest the fiery aspect of the disk of the setting sun; further, Heracles crosses Oceanus in the golden cup or boat of the sun-god Helios. Geryon (from γηρύω, the howler or roarer) is supposed to personify the storm, his father Chrysaor the lightning, his mother Callirrhoë the rain. The cattle are the rain-clouds, and the slaying of their keepers typifies the victory of the sun over the clouds, or of spring over winter. The euhemeristic explanation of the struggle with the triple monster was that Heracles fought three brothers in succession.
See Apollodorus ii. 5. 10; Hesiod, Theogony, 287; Diod. Sic. iv. 17; Herodotus iv. 8; F. Wieseler in Ersch and Gruber, Allgemeine Encyclopädie; F. A. Voigt in Roscher’s Lexikon der Mythologie; L. Preller, Griechische Mythologie; article “Hercules” in Daremberg and Saglio, Dictionnaire des antiquités.