Prometheus was the son of Iapetus who was one of the Titans. He tricked the gods into eating bare bones instead of good meat. He stole the sacred fire from Zeus and the gods. Prometheus did not tell Zeus the prophecy that one of Zeus's sons will overthrow him. In punishment, Zeus commanded that Prometheus be chained for eternity in the Caucasus. There, an eagle (or, according to other sources, a vulture) would eat his liver, and each day the liver would be renewed. So the punishment was endless, until Heracles finally killed the bird.
According to Friedrich Nietzsche in `The Birth of Tragedy`:
The Prometheus saga is a primordial possession of the Aryan population collectively and documentary evidence of their talent for the profoundly tragic. In fact, it could be the case that for the Aryan being this myth has the same defining meaning as the myth of the Fall has for the Semitic peoples, and that both myths are, to some degree, related, as brother and sister.
The pre-condition of this Prometheus myth is the extraordinary value which a naïve humanity associates with fire as the true divine protector of that rising culture. But the fact that man freely controls fire and does not receive it merely as a gift from heaven, as a stirring lightning flash or warming rays of the sun, appeared to these contemplative primitive men as an outrage, a crime against divine nature. And so right there the first philosophical problem posed an awkward insoluble contradiction between man and god and pushed it right up to the door of that culture, like a boulder. The best and loftiest thing which mankind can share is achieved through a crime, and people must now accept the further consequences, namely, the entire flood of suffering and troubles with which the offended divine presences afflict the nobly ambitious human race. Such things must happen — an austere notion which, through the value which it gives to a crime, stands in a curious contrast to the Semitic myth of the Fall, in which curiosity, lying falsehoods, temptation, lust, in short, a row of predominantly female emotions are look upon as the origin of evil.
What distinguishes the Aryan conception is the lofty view of an active transgression as the essentially Promethean virtue. With this, the ethical basis of pessimistic tragedy is established together with the justification of human evil, that is, human guilt as the penalty for that sin. The impiety in the essence of things — that’s what the thinking Aryan is not inclined to quibble away. The contradiction in the heart of the world reveals itself to him as the interpenetration of different worlds, for example, a divine and human world, each one of which is right in its separate way but which must suffer for its individuality as the two worlds come close together.