Hercules was the son of Zeus, the chief god of the ancient Greeks, and a mortal woman. He had a reputation for great strength. This strength was apparent even as an infant, when he strangled two large snakes.
His strength also landed him in trouble. In a fit of madness caused by Hera, he killed his wife and sons. For his punishment, he had to serve his cousin Eurystheus. Eurystheus was afraid of Hercules and wanted him to be killed, so he ordered Hercules to do twelve labors. Though these labors were very dangerous, Hercules accomplished them all.
Even though the labors had been completed, Hercules kept getting into trouble. Finally his luck ran out. His mortal part, which he had from his mother, died. He was changed into an immortal and joined the other gods and goddesses on Mt. Olympus.