Prometheus was a cousin of Zeus,
according to one tradition he created the first men and always defended
them from the anger of gods. Once he stole for mankind the sacred Olympian
fire. To punish the mankind Zeus send them Pandora.
To punish Prometheus, Zeus ordered him to be chained to a rock in the Caucasus
and sent an eagle to consume his liver, which continually renew itself.
Zeus swore that Prometheus would never be released. Heracles,
however, traveling though Caucasus, shot the eagle and released Prometheus.
Zeus did not protest against his son’s deed. Prometheus possessed the power
of prophecy and in his turn helped Heracles in his next labour.
See: Peter Paul Rubens Chained
Prometheus.