In Greek mythology, Geryon (Geryones, Geyron), son of Chrysaor and Callirrhoe and grandson of Medusa was a fearsome giant who dwelt on 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 southern Iberia. Geryon was often described as a monster with human faces. Geryon had three heads and three bodies with a total of six arms. Some accounts state that he had six legs as well while others state that the three bodies were joined to one pair of legs. Although there are some mid-sixth century Chalcidian vases portraying Geryon as winged, it is not known whether Stesichorus' Geryon had wings: it seems unlikely. Apart from these weird features, 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 herder Eurytion, son of Erytheia.
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 watchdog. Eurytion the herdsman came to assist Orthrus, but Heracles dealt with him the same way.
On hearing the commotion, Geryon sprang into action, carrying three shields, three spears, and wearing three helmets. He pursued Heracles at the River Anthemus but fell a victim to an arrow that had been dipped in the venomous blood of the Lernaean Hydra, shot so forcefully by Heracles that it pierced Geryon's forehead, "and Geryon bent his neck over to one side, like a poppy that spoils its delicate shapes, shedding its petals all at once 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 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 had hidden the stolen animals, and they began calling out to each other. In others, Caca, Cacus' sister, told Heracles where he was. Heracles then killed Cacus, and according to the Romans, 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. The hero was within a year able to retrieve them. Hera then sent a flood which raised the level of a river so much, Heracles could not cross with the cattle. He piled stones into the river to make the water shallower. When he finally reached the court of Eurystheus, the cattle were sacrificed to Hera.
The fragments are sufficient to show that the poem was composed in twenty-six line triads, of strophe, antistrophe and epode, repeated in columns along the original scroll, facts that aided Page in placing many of the fragments, sometimes of no more than a word, in their proper positions.