In Greek legend and literature, the Cyclops, the one-eyed monstrous giants were considered as the children of Uranus, the personification of the sky or heavens, and Gaea, the earth. They were known to be the workmen of the God Hephaestus, whose workshop was in the heart of the volcanic mountain Etna. Their name is also spelt as Cyclopes and different stories about them mainly appear in the works of Hesiod, an ancient Greek poet generally thought to have been active between 750 and 650 BC and Homer, the presumed author of the Iliad and the Odyssey, the  two epic poems that are the central works of ancient Greek literature. While the Cyclops and their role in the war of Titanomachy was depicted in Hesiod’s Theogony, Cyclops and the encounter between Polyphemus and Odysseus is told in Homer’s Odyssey.

Hesiod in his ‘Theogony’ mentioned three Cyclops,  Arges (Thunderer), Steropes (Lightner), and Brontes (Vividly Bright), the immensely strong sons of Uranus and Gaea with a single eye in the middle of their foreheads, who were some of the earliest gods, born after the Titans. However, as Uranus apprehended that his sons will ultimately overthrow and kill him, he imprisoned the hundred-handed Hecatonchires and the one-eyed Cyclopes in Tartarus, the Underworld. This enraged Gaea and to teach him a lesson, she created a great stone sickle and persuaded her sons to castrate their father. Instigated by his mother, Cronus castrated and overthrew his father Uranus, established himself as the supreme ruler of all gods, but did not release the Hecatonchires and the Cyclopes and commanded the dragon Campe to guard them.

However, Cronus was also scared of his children, as his father Uranus predicted that, one day one of his sons would overthrow him. Consequently, he consumed all the children immediately after their birth, except Zeus, who was tactfully saved by his mother. Ultimately, Zeus released the imprisoned Cyclopes and the Hecatoncheires and all of them fought together along with Zeus in the war of Titanomachy, the war between the old generation of Greek gods and the Olympian gods, led by Zeus, in which the Olympians successfully drove their opponents into the pit of Tartarus.

In the said war, Zeus used the thunderbolts as his weapon, which were created by the Cyclopes, the workmen of the God Hephaestus. They also forged a trident for Poseidon and the Helmet of Darkness for Hades. Apart from that they were credited with making the altar at which Zeus and his allies swore allegiance before that war. Eventually, the altar was placed in the sky, as the constellation known as Ara, which stands for  Altar in Latin. 

Legend says, the Cyclops brothers were killed by the Sun god Apollo, after they struck his son, or were wrongly blamed for striking his son Aesculapius with lightning.

Besides Hosiod’s Theogony, the Cyclops also appears in Homer’s Odyssey, where they were depicted as sons of Poseidon, but share with Hesiod's Cyclopes immensity, strength, and the single eye. However, in Homer’s epic, the Cyclops were shepherds, not metalworkers. When Odysseus and his crew landed on the island of Sicily, resided by the Cyclops and led by the man-eating giant Cyclops Polyphemus, the sailors discovered Polyphemus' cave, in which he stored enormous numbers of crates of cheese, as well as pens full of lambs. As the owner of the cave was out with his sheep and goats, Odysseus insisted his men not to steal and run away, but to wait and meet the owner. When Polyphemus returned, he drove his flocks into the cave and closed the mouth of the cave, moving a mighty boulder across the entrance.

The sailors did not know that Polyphemus was a man-eating monster and when he found the unknown men in the cave, he seized two of them, dashed their brains out and ate them for supper. The next morning, he killed and ate another two men for breakfast and then drove the sheep out of the cave blocking the entrance behind him. As they were entrapped in the cave, Odysseus had no option but to devise a quick escape plan. In the evening, when the monster returned to his cave, Odysseus offered him some very powerful wine, which made him intoxicated. The sailors took the opportunity and gouged out his eye with a sharpened stick. The next morning, when Polyphemus opened the cave to take his flock out to the fields, Odysseus and his men secretly clinging under the bellies of the animals and thus escaped from the other Cyclops.