To accomplish his tenth labour, Hercules had to journey to the end of the world. Eurystheus ordered the hero to bring him the cattle of the monster Geryon. Geryon was the son of Chrysaor and Callirrhoe. Chrysaor had sprung from the body of the Gorgon Medusa after Perseus beheaded her, and Callirrhoe was the daughter of two Titans, Oceanus and Tethys. With such distinguished ancestors, it is no surprise that Geryon himself was quite unique. It seems that Geryon had three heads and three sets of legs all joined at the waist.

And the daughter of Ocean, Callirrhoe... bore a son who was the strongest of all men, Geryones, whom mighty Heracles killed in sea-girt Erythea for the sake of his shambling oxen.

Geryon lived on an island called Erythia, which was near the boundary of Europe and Libya. On this island, Geryon kept a herd of red cattle guarded by Cerberus's brother, Orthus, a two-headed hound, and the herdsman Eurytion. Hercules set off on for Erythia, encountering and promptly killing many wild beasts along the way, and he came to the place where Libya met Europe.

Here, Hercules built two massive mountains, one in Europe and one in Libya, to commemorate his extensive journey. Other accounts say that Hercules split one mountain into two. Either way, these mountains became known as the Gates or Pillars of Hercules. The strait Hercules made when he broke the mountain apart is now called the Strait of Gibraltar, between Spain and Morocco, the gateway from the Mediterranean Sea to the Atlantic Ocean.

Sailing in a goblet which the Sun gave him in admiration, Hercules reached the island of Erythia. Not long after he arrived, Orthus, the two-headed dog, attacked Hercules, so Hercules bashed him with his club. Eurytion followed, with the same result. Another herdsman in the area reported these events to Geryon. Just as Hercules was escaping with the cattle, Geryon attacked him. Hercules fought with him and shot him dead with his arrows.

The stealing of the cattle was not such a difficult task, compared to the trouble Hercules had bringing the herd back to Greece. In Liguria, two sons of Poseidon, the god of the sea, tried to steal the cattle, so he killed them. At Rhegium, a bull got loose and jumped into the sea. The bull swam to Sicily and then made its way to the neighbouring country. The native word for bull was "italus," and so the country came to be named after the bull, and was called Italy.

The escaped bull was found by a ruler named Eryx, another of Poseidon's sons, and Eryx put this bull into his own herd. Meanwhile, Hercules was searching for the runaway animal. He temporarily entrusted the rest of the herd to the god Hephaestus, and went after the bull. He found it in Eryx's herd, but the king would return it only if the hero could beat him in a wrestling contest. Never one to shy away from competition, Hercules beat Eryx three times in wrestling, killed the king, took back the bull, and returned it to the herd.

Hercules made it to the edge of the Ionian Sea, with the end of his journey finally in sight. Hera, however, was not about to let the hero accomplish this labour. She sent a gadfly to attack the cattle, and the herd scattered far and wide. Now, Hercules had to run around Thrace gathering the escaped cows. Finally, he regrouped the herd and, blaming his troubles on the river Strymon in Thrace, he filled the river with rocks, making it unnavigable. Then, he brought the cattle of Geryon to Eurystheus, who sacrificed the herd to Hera.

The ancients don't tell us how long either Hercules or Europe took to recover from this adventure!