Prometheus was a god who loved humans most of all gods. He taught them many arts and sciences. One day he stole the fire from Zeus and gave it to humans, to help them improve their civilization. Zeus raged, commands god Hephaistos to chain Prometheus on a mountain all alone, away from gods and humans. Hephaistos executes Zeus's command.
Prometheus, who was a prophet, asks from Zeus to release him and in return he would tell him who, when and how would take his throne from him. Zeus replies that if he would not tell him who could threaten his throne he would send a vulture to eat Prometheus's liver every day. The liver would heal at night and the vulture would continue the day after and the suffering would go on and on. Prometheus refused and Zeus sent the vulture.
Finally Zeus, impressed by Prometheus's courrage, he put asside his rage,released Prometheus, who returned to Olympus and lived with the immortals.