16th century engraving by Johan Sluperius. A cyclops in Greek mythology and later Roman mythology, was a member of a primordial race of giants, each with a single eye in the middle of his forehead. Hesiod described one group of cyclopes and the epic poet Homer described another; other accounts were written by the playwright Euripides, poet Theocritus and Roman epic poet Virgil. In Hesiod's Theogony, Zeus releases three Cyclopes, the sons of Uranus and Gaia, from the dark pit of Tartarus. They provide Zeus' thunderbolt, Hades' helmet of invisibility, and Poseidon's trident, and the gods use these weapons to defeat the Titans.