Prometheus, the Titan, whose name means ‘foresight’, created Man and "... bade him to stand erect and turn his eyes to heaven." [Ovid, Metamorphoses 1.85]
Upon repeated requests by his brother Epimetheus, Prometheus agreed to let him distribute the Gifts among all creation. Epimetheus, devoid of foresight, distributed the gifts randomly among all creation, giving some wings to flee, others tooth and fang to kill, strength to some and speed to some. He gave them resistance to weather and provided for food that some may feed on grass and some on the flesh of others.
And what for Man? There was nothing left. Pained at this injustice toward his most loved creation, Prometheus stole wisdom and art from Hephaestus and Athena and gave it to Man. Most importantly, he stole Fire, that was till then a priviledge of the Olympians, and bestowed it upon Man. For this thievery, Zeus had him chained to a rock on Mount Caucasus where every day an eagle swooped on him and devoured the lobes of his liver, which grew by night as much as the eagle had devoured during the day.
Despite the tyranny of Zeus, Prometheus twice saved his life and position. The first, in the war against the greater tyrant Cronos and later by averting Zeus’ marriage to Thetis that would have resulted in a Nereid offspring destined to overthrow Zeus. Prometheus was then freed from the daily torture upon Mount Caucasus when Heracles finally killed the eagle upon the command of a thankful Zeus. Till that day, Prometheus had suffered his torture for thirty thousand years.
Though mankind dubbed him ‘The Benefactor’, Zeus never gave Prometheus the immortality of a Titan. The centaur Chiron was grievously wounded by Heracles’ arrow. However, being an immortal, he could not die though he wished for it, and would have been condemned to living for an eternity with the wound. Prometheus, the benefactor, offered to take both Chiron’s wound and immortality and Zeus consented.
However, Zeus did not release Prometheus from all binding, since he had sworn to that, but for commemoration bade him bind his finger with stone and iron. And that is why, men adopted the custom of wearing rings fashioned of stone and iron, that they may seem to appease Prometheus.