Labors of Hercules. The Twelve Labours of Heracles or Hercules are a series of episodes concerning a penance carried out by Heracles, the greatest of the Greek heroes, whose name was later romanised as Hercules. They were accomplished at the service of King Eurystheus. The episodes were later connected by a continuous narrative. The establishment of a fixed cycle of twelve labours was attributed by the Greeks to an epic poem, now lost, written by Peisander, dated about 600 BC. After Heracles killed his wife and children, he went to the oracle at Delphi. He prayed to the god Apollo for guidance. Heracles was told to serve the king of Mycenae, Eurystheus, for ten years. During this time, he is sent to perform a series of difficult feats, called labours. Driven mad by Hera, Heracles slew his sons by his wife Megara. After recovering his sanity, Heracles deeply regretted his actions; he was purified by King Thespius, then traveled to Delphi to inquire how he could atone for his actions. Pythia, the Oracle of Delphi, advised him to go to Tiryns and serve his cousin, King Eurystheus, for ten years, performing whatever labours Eurystheus might set him; in return, he would be rewarded with immortality. Heracles despaired at this, loathing to serve a man whom he knew to be far inferior to himself, yet fearing to oppose his father Zeus. Eventually, he placed himself at Eurystheus's disposal. Eurystheus originally ordered Heracles to perform ten labours. Heracles accomplished these tasks, but Eurystheus refused to recognize two: the slaying of the Lernaean Hydra, as Heracles' nephew and charioteer Iolaus had helped him; and the cleansing of the Augeas, because Heracles accepted payment for the labour. Eurystheus set two more tasks, which Heracles also performed, bringing the total number of tasks to twelve. As they survive, the labours of Heracles are not recounted in any single place, but must be reassembled from many sources. Ruck and Staples assert that there is no one way to interpret the labours, but that six were located in the Peloponnese, culminating with the rededication of Olympia. Six others took the hero farther afield, to places that were, per Ruck, all previously strongholds of Hera or the 'Goddess' and were Entrances to the Netherworld. In each case, the pattern was the same: Heracles was sent to kill or subdue, or to fetch back for Eurystheus a magical animal or plant. A famous depiction of the labours in Greek sculpture is found on the metopes of the Temple of Zeus at Olympia, which date to the 450s BC. In his labours, Heracles was sometimes accompanied by a male companion, according to Licymnius and others, such as Iolaus, his nephew. Although he was supposed to perform only ten labours, this assistance led to two labours being disqualified: Eurystheus refused to recognize slaying the Hydra, because Iolaus helped him, and the cleansing of the Augean stables, because Heracles was paid for his services and/or because the rivers did the work. Several of the labours involved the offspring of Typhon and his mate Echidna, all overcome by Heracles. A traditional order of the labours found in the Bibliotheca by Pseudo-Apollodorus is: Slay the Nemean lion. Slay the nine-headed Lernaean Hydra. Capture the Ceryneian Hind. Capture the Erymanthian Boar. Clean the Augean stables in a single day. Slay the Stymphalian birds. Capture the Cretan Bull. Steal the Mares of Diomedes. Obtain the girdle of Hippolyta, queen of the Amazons. Obtain the cattle of the three-bodied giant Geryon. Steal three of the golden apples of the Hesperides. Capture and bring back Cerberus. Heracles wandered the area until he came to the town of Cleonae. There he met a boy who said that if Heracles slew the Nemean lion and returned alive within 30 days, the town would sacrifice a lion to Zeus, but if he did not return within 30 days or if he died, the boy would sacrifice himself to Zeus. Another version claims that he met Molorchos, a shepherd who had lost his son to the lion, saying that if he came back within 30 days, a ram would be sacrificed to Zeus. If he did not return within 30 days, it would be sacrificed to the dead Heracles as a mourning offering. While searching for the lion, Heracles fletched some arrows to use against it, not knowing that its golden fur was impenetrable. When he found and shot the lion, firing at it with his bow, he discovered the fur's protective property as the arrow bounced harmlessly off the creature's thigh. After some time, Heracles made the lion return to his cave. The cave had two entrances, one of which Heracles blocked; he then entered the other.