Prometheus was the only Titan wise enough to side with Zeus and his brothers and sisters in the war after Zeus's rebellion against Cronus.
Although Zeus owed Prometheus much for helping the gods, Zeus punished him harshly after Prometheus helped mankind. Prometheus stole fire from the heavens and arranged so that the gods received the fat and bones of animals rather than the best part by taking sacrificed animals and cleverly disguising the good parts as the worst parts and the worst parts as good parts. Zeus punished Prometheus by imprisoning him at Caucasus, a mighty mountain. Zeus also wanted Prometheus to reveal who would be born that would overthrow Zeus.
Prometheus's eventual rescue is not clear. One account stated that Hercules came to slay the eagle preying on Prometheus, setting him free. Another account stated that Chiron sacrificed his life to save Prometheus, and Zeus accepted this.
The task of creating the first human beings were said to have been given to Prometheus and his brother Epimetheus. Epimetheus allotted all the good assets to animals, so Prometheus gave the two things that made man superior to animals: high intelligence and an upright posture. In addition, Prometheus stole fire to give to man to defend themselves.
At the time he was bound, Prometheus met a heifer who appeared below from the cliffs. He recognized her as Io, who had been turned into a cow by Zeus after Hera became suspicious of her. Prometheus comforted her, and told her distant future that once she reached the Nile Zeus would turn her back to a human.