Prometheus, whose name means "forethought", was the brother of Epimetheus. During the war of the Titans, Prometheus, foreseeing the victory of Zeus, fought on the Olympians side. Epimetheus, looking to the past, kept fighting with the Titans.
After the victory, Prometheus was given the task by Zeus of creating all life on Earth. He then also made humans from clay without Zeus' permission. This upset Zeus; but Prometheus was able to save humanity.
At the first animal sacrifices, Prometheus tricked Zeus into choosing the bones and entrails for the gods' portion by wrapping them in enticing fat, while the choice cuts were hidden under the stomach. This resulted in human celebrants receiving the choice meats at future animal sacrifices.
Prometheus was reputed to have felt pity on the early days of humanity, and decided to share with them the gift of fire, which only the deities knew. For this, he was punished by being chained to a pole on the side of a mountain and have his subsequently regenerating liver eaten day after day by an eagle. To punish humanity, Zeus sent Pandora along with Pandora's box.
After 30,000 years, Prometheus was released from his torture because he possessed a great secret. This secret was that Zeus could only be overthrown by a child he fathered by the nymph Thetis.