In the fullest account in the Bibliotheke of Pseudo-Apollodoros, Heracles was required to travel to the far-off western Mediterranean island of Erytheia, in order to obtain the Cattle of Geryon as his tenth labour. On the way there, he crossed the Libyan desert and became so frustrated at the heat that he shot an arrow at Helios, the Sun. Helios “in admiration of his courage” gave Hercules the golden cup he used to sail across the sea from west to east each night. Hercules used it 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.
When Hercules 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 Hercules 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 Hercules at the River Anthemus but fell 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”.
Hercules 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 Hercules, 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.