Driven mad by Hera, Herakles slew his wife Megara and their children. After recovering his sanity, he traveled to the Sanctuary of Delphi to inquire how he could atone for his actions; he was instructed by the Pythia to go to Tiryns and serve his cousin, King Eurystheus, for twelve years. Therefore, Eurystheus set twelve tasks for Herakles. 
List of the labours
- Slay the Nemean Lion
- Slay the Lernaean Hydra
- Capture the Hind of Keryneia
- Capture the Erymanthian Boar
- Clean the Stable of Augeias
- Slay the Stymphalian birds
- Capture the Kretan Bull
- Steal the mares of Diomedes
- Obtain the girdle of Hippolyta
- Obtain the cattle of Geryon
- Steal the apples of Hesperides
- Subdue and take back Cerberus from the underworld.
- In Assassin's Creed: Odyssey, metopes depicting seven of Herakles' labours can be found decorating temples in numerous places, most notably the Temple of Zeus within the Sanctuary of Olympia in Elis. These metopes are reproductions of historical metopes.
- While unconnected to his atonement there is an event jokingly and informally referred to as the Thirteenth Labor where Herakles impregnated the fifty daughters of Thespius, king of Thespiae, in a single night. Many dynastic lines trace their lineage back to this event, including the Agiads and Eurypontids of Sparta, the Argeads of Makedonia, and many others.