In Greek mythology, Geryon (Geryones,Geyron), son of Chrysaor and Callirhoe, was a winged titan who dwelt in the island Erytheia of the mythic Hesperides in the far west of the Mediterranean. A more literal-minded later generation of Greeks associated the region with Tartessos, in the province of Cadiz in southern Spain. Geryon had three heads, three bodies, and six arms. His three bodies were conjoined at the waist and his appearance was that of a warrior. He owned a two-headed hound named Orthrus, which was the brother of Cerberus, and a herd of magnificent red cattle that were guarded by Orthrus, and a man named Eurythion.
Heracles' Journey to Erytheia (location of the Cattle of Geryon)
Heracles was required to obtain the Cattle of Geryon as his tenth labour. While journeying there, he crossed the Libyan desert (Libya was the generic name for Africa to the Greeks), and was so frustrated at the heat that he shot an arrow at Helios, the sun. Helios begged him to stop, and Heracles demanded the golden cup used by Helios to sail across the sea each night. Heracles used the cup to reach Erytheia, a favorite motif of the vase-painters. Such a magical conveyance undercuts any literal geography for Erytheia, the "red island" of the sunset.
Theft of the Cattle of Geryon
When Heracles reached Erytheia, no sooner had he landed than he was confronted by the two-headed dog Orthrus. With one huge blow from his olive-wood club, Heracles killed the watch-dog. Eurythion the herdsman came to assist Orthrus, but Heracles overcame this attack in the same manner.
On hearing the commotion, Geryon became mad and sprang into action, carrying three shields, three spears, and wearing three helmets. He pursued Heracles at River Anthemus but fell a victim to an arrow of the hero that had been dipped in the venomous blood of the Lernaean Hydra, shot so forcefully that it pierced all three bodies of Geryon. And with a shrill, despairing groan, Geryon swayed, then fell, nevermore to rise. In some versions, Heracles tore Geryon's bodies into three separate pieces.
Heracles then had to herd the cattle back to Eurystheus. In Roman versions of the narrative, on the Aventine hill in Italy, Cacus stole some of the cattle stolen from Geryon as Heracles slept, making the cattle walk backwards so that they left no trail, a repetition of the trick of the young Hermes. According to some versions, Heracles drove his remaining cattle past a cave, where Cacus was hiding the stolen ones, and they began calling out to each other, but in others, Caca, Cacus' sister, told Heracles where he was. Heracles then killed Cacus, and according to the Romans, then founded an altar where the Forum Boarium, the cattle market, was later held.
To annoy Heracles, Hera sent a gadfly to bite the cattle, irritate them and scatter them. Hera then sent a flood which rose the level of a river so much Heracles could not ford the cattle. He piled stones into the river to make the water shallower. Heracles then had to kill a monster that was half-woman and half-serpent. When he finally reached the court of Eurystheus, the cattle were sacrificed to Hera.