After a fit of madness sent by Hera, Heracles butchered his wife and children. He left his home in Thebes and, commanded by the Oracle at Delphi, he went to Tiryns and serve the king Eurystheus for twelve years, accomplishing ten labors. The Pythia said that by doing this, Heracles would become immortal.
Eurystheus, fearful of the power of Heracles, hoped to kill him by assigning the impossible. He even did not accept two of the labors after being completed, making the actual number of labors twelve instead of ten. Heracles was able to do each, however, and by doing so achieved immortality through apotheosis.
1. The Nemean Lion
The first of the twelve labors given to Heracles by the king Eurystheus was to kill this mighty beast. As Heracles soon found out, no weapon could pierce its tough hide. Heracles had to resort to fighting the Nemean Lion with his bare hands, eventually strangling it to death.
Once dead, Heracles brought the dead beast back to a stunned Eurystheus, who had assumed the hero would be killed. Afraid the king forbid Heracles to enter the gates, and instead he gave him the second labor using a herald.
2. The Lernaean Hydra
An offspring of Echidna and Typhaon, the Hydra is is a serpent-like creature with nine heads, one of which is immortal. Moreover, each time a head is cut off, two more grow up in its place. To defeat it, Heracles cut of the heads and had his friend Iolaus who pressed down with a branding iron, searing the wound so that two more heads would not be created. Heracles then hid the immortal head under a rock. Heracles then dipped his arrows into its blood, so that his enemies would be poisoned with the blood.
When he returned to Eurystheus, however, the weak king declared that this labor did not count, since Heracles had enlisted the help of a friend.
3. The Cerynitian Hind
Eurystheus ordered Heracles to bring him this hind, which was sacred to the goddess Artemis, alive. This creature was exceptionally swift, and he chased it for a year with no success. At last, he wounded the creature with an arrow, thereby slowing it enough to be captured. He then took it alive back to Tiryns. Enraged, Artemis wanted to take the hind from Heracles, but he explained that it was not his fault, but Eurystheus'
4. The Erymanthian Boar
Heracles was ordered to bring in this beast alive. While traveling to Mt. Erymanthos, Heracles accidentally killed Cheiron, the famous king of the Centaurs. Heracles then proceeded to capture the Boar by trapping it in the snow of a mountain.
5. The Cattle of Augeias
Eurystheus ordered Heracles to clean the fields of king Augeias without help in one day. Since Augeias knew nothing of Eurystheus' order, Heracles first went to the king and said he would clean the stables for a price: one-tenth of his cattle. Augeias quickly agreed, believing the task impossible.
Heracles then diverted the flow of two nearby rivers, cleaning off the dung from all of the land. When he returned to Augeias and demanded his pay, the king refused, saying that he had made no such promise. Heracles was driven from the town.
When Heracles returned to Tiryns, Eurystheus refused to accept this labor. He said that since Heracles had worked for pay, it did not count.
6. The Stymphalian Birds
Eurystheus ordered Heracles to drive away the birds, which crowded lake Stymphalia. Heracles was at a loss as to how to drive them all away, until he was helped by the goddess Athena. She gave him castanets forged by Hephaestus. These were so loud that they drove the birds completely away from the lake.
7. The Cretan Bull
For the seventh labor, Heracles was ordered to retrieve the Cretan Bull alive. He captured the bull with little difficulty, then took it back to Tiryns.
8. The Mares of Diomedes
For his eighth labor, Eurystheus ordered the hero to bring him the mares of the King Diomedes, who possessed man-eating horses. Gathering a group of volunteers, Heracles captured the horses and took them to Tiryns.
9. The Belt of Hippolyte
Hippolyte is one of the queens of the Amazons, and Heracles' task was to retrieve her belt. Eurystheus assigned this task because his daughter desired to wear it. Hippolyte was willing to give him her belt, but because of Hera, Heracles was forced to kill her.
While sailing back, he stopped at Troy. There he saved the daughter of Laomedon, but the foolish king would not give him the promised reward. Angry, Heracles promised to return and destroy the city.
10. The Cattle of Geryon
Geryon, a grandson of Oceanus, inhabited an island on the ocean. He owned red cattle, which were guarded by a shepherd and Geryon's dog, Orthos. Heracles' task was to drive the cattle to Tiryns. Only with great difficulty did he accomplish this, and many of the cattle were lost along the way.
11. The Apples of the Hesperides
As the eleventh labor, Eurystheus ordered Heracles to retrieve some golden apples from the Hesperides. On the journey, Heracles encountered Prometheus, still being tortured for defying Zeus. He shot the eagle, which daily devoured his liver. Then, he set Prometheus free. In exchange, he presented Cheiron to Zeus. As thanks, Prometheus gave Heracles advice on how to best obtain some golden apples.
Following the advice of Prometheus, Heracles went to Atlas for help. Atlas took three apples, but was unwilling to assume his burden once again. Through trickery, Heracles got Atlas to resume his eternal punishment. After he showed the apples to Eurystheus, Athena then carried them back to the Hesperides.
12. The Capture of Cerberus
As the last of his labors, Heracles was ordered by Eurystheus to bring back Cerberus from the underworld alive. While in the underworld, Heracles encountered the hero Theseus, whom he rescued. Forbidden by Hades, Heracles used no weapons. He wrestled with the dog until he had broken its will. He then rode the dog back to Tiryns and showed it to Eurystheus.
After completing the twelve labors, Heracles became an immortal, just as the oracle had said. He was not immediately taken to Olympus, but instead remained on the earth for some time as a mortal.