After killing his family in an insane rage, Herakles (also known as Hercules) received orders from the oracle at Delphi to perform 12 labors to purge his sin. These were assigned by Eurystheus, king of Mycenae.
Eurystheus next sent Herakles to capture a stag sacred to Artemis. This was less a test of strength, and more one of endurance. The stag led him on a year long chase before it could run no more. Herakles bound the stags legs, hoisted it around his neck, and walked straight into Artemis, who stood there with arrow drawn against him.
Herakles kept his head, dropped the stag, knelt before Artemis, and explained he was following the instructions of her brother, Apollo. A little bargaining, and she allowed him to carry the prize to Eurystheus, provided the stag was returned to the forest when the task was done.
Thus ended the third labor. Click here for the fourth.