Gigantomachy

In Greek mythology, the Giants, also called Gigantes (jye-GAHN-tees or gee-GAHN-tees; Greek: Γίγαντες, Gigantes, singular Γίγας, Gigas) were a race of great strength and aggression, though not necessarily of great size, known for the Gigantomachy (Gigantomachia), their battle with the Olympian gods. According to Hesiod, the Giants were the offspring of Gaia (Earth), born from the blood that fell when Uranus (Sky) was castrated by his Titan son Cronus.

Archaic and Classical representations show Gigantes as man-sized hoplites (heavily armed ancient Greek foot soldiers) fully human in form. Later representations (after c. 380 BC) show Gigantes with snakes for legs. In later traditions, the Giants were often confused with other opponents of the Olympians, particularly the Titans, an earlier generation of large and powerful children of Gaia and Uranus.

The vanquished Giants were said to be buried under volcanoes and to be the cause of volcanic eruptions and earthquakes.

The name "Gigantes" is usually taken to imply "earthborn", and Hesiod's Theogony makes this explicit by having the Giants be the offspring of Gaia (Earth). According to Hesiod, Gaia mating with Uranus bore many children: the first generation of Titans, the Cyclopes and the Hundred-Handers. But Uranus hated his children and, as soon as they were born, he imprisoned them inside of Gaia, causing her much distress. And so Gaia made a sickle of adamant which she gave to Cronus, the youngest of her Titan sons, and hid him (presumably still inside Gaia's body) to wait in ambush. And when Uranus came to lie with Gaia, Cronus castrated his father, and "the bloody drops that gushed forth [Gaia] received, and as the seasons moved round she bore ... the great Giants." From these same drops of blood also came the Erinyes (Furies) and the Meliai (ash tree nymphs), while the severed genitals of Uranus falling into the sea resulted in a white foam from which Aphrodite grew. The mythographer Apollodorus also has the Giants being the offspring of Gaia and Uranus, though he makes no connection with Uranus' castration, saying simply that Gaia "vexed on account of the Titans, brought forth the Giants".

...
Wikipedia