As punishment for killing his wife and children in a fit of insanity, Herakles was sentenced by the oracle of Apollo to serve Eurystheus, the king of Tiryns and Mycenae, for twelve years. As part of his sentence, Eurystheus required that Herakles complete twelve seemingly impossible labors - the first of which was to bring back the skin of the lion terrorizing the hills around Nemea. Soon after tracking the ferocious beast, Herakles realized that his arrows and club were useless against the thick pelt and he would need to find another way to dispatch his prey. Following the lion to a cave, Herakles blocked one of the two entrances and approached the lion through the other. Grasping the lion tightly in his powerful arms, the hero wrestled with the beast until it was strangled to death. Herakles proceeded to skin the lion using the beast's own sharp claws and then threw the pelt over himself as a cloak which would protect him in his future labors. From this time on the skin of the Nemean lion would become one of the attributes associated with Herakles.