The Cyclopes are giants with only one eye in the middle of their foreheads. The original three were sons of Gaia and Uranus, and therefore brothers of Cronus. They were imprisoned in Tartarus during the Titanomachy until freed by the heroes and Olympians. As smiths, they forged Zeus' Thunder Bolts Poseidon's Trident, and Hades' Helmet of Darkness. Polyphemus, a son of Poseidon, was also a cyclops and was blinded by Odysseus, and has held a bitter resentment of him ever since.