Gigantomachy, the War of the Giants
Gigantomachy was a great war, fought between Olympian Gods and Giants for power and dominion of the Cosmos. It is said that Gaea, the mother goddess of the earth, became enraged due to imprisonment and oppression of her direct descendants, the Titans, in Tartarus. In anger, she gave birth to a new generation of giants in Phlegra (Pallene), where the battle later unfolded. These giants were said to be powerful, massive beings with a thunderous noise as they emerged from the earth, a monstrous breed aimed at challenging the heaven. Some of them were immortal in their native lands, impossible to defeat by any divine entity, such as Alcyoneus, one their leaders. Gaea urged them to rebel against Zeus and his order with a promise they will become the next rulers of the cosmos. In Claudian's Gigantomachia, the giants were imagining they would take the realms, Porphyrion dreaming of ruling Delphi, Enceladus of the seas, and Typhoeus of the heavens and that they have imprisoned Poseidon, captured Ares and defiled other gods. Some giants even believed they would marry goddesses such as Athena, Artemis and Aphrodite.
The great battle unfolds
The stage was all set and the Olympians did not shy away from the conflict. They have prepared for this as Heracles is called upon for help, summoned by Athena to the battlefield, after Zeus had been told by an oracle that assistance from a mortal would be required to defeat the rebels. The great battle has commenced when entire landscapes were thrown into disarray, uprooting mountains and islands, diverting rivers, as the giants began using elements of the earth as their weapons. Some giants were seen wielding massive mountain ranges like Thessalian Oeta and Athos.
Ares was among the first gods to engage in battle, attacking a giant named Pelorus and killing him with a single strike. It is said that he killed three entities in one blow, the giant and two serpent bodies.
Athena fought Pallas and ended up flaying him, to use the skin as armor to shield her own body. Another casualty was Palleneus, who was struck down by her sword, after engaging in direct combat with the goddess. She also pursued Enceladus and, by throwing the island of Sicily on him, ended his life when the giant fled the battlefield. Athena was also recorded to have defeated many giants by invoking her Gorgon’s head on her breastplate which was enough to incapacitate them, render them immobile or petrify them.
One of the most notable battles was between Heracles and Alcyoneus where the hero shot down the giant with an arrow. Alcyoneus fell to the ground but, since he was immortal in his homeland, somewhat revived. While recovering, Heracles, after being advised by Athena, dragged him outside Pallene where he was able to deal the final blow to the giant. The other leader Porphyrion was struck down by Zeus' thunderbolt when he was about to violate Hera, after tearing down her robes. While incapacitated, Heracles siezed the opportunity and killed him with an arrow.
With combined effort, Apollo and Heracles managed to defeat Ephialtes. The god's arrow landed in the left eye while the hero's arrow hit the right eye of the giant, rendering him immobile.
Poseidon fought Polybotes and chased him over seas to the island Cos where he was finally able to overcome the giant by throwing a piece of the island Nisyrium on him.
Other battles included Dionysus killing Eurytus with Thyrsus (the magical staff), Hermes defeating Hippolytus in a fight while wearing Hades' helm of darkness, Hephaestus slaying Mimas with lava missles, Hecate using torches to burn Clytius, Fates killing Agrius and Thoas with brazer clubs and Artemis ending the life of Gration. The rest were said to be destroyed by Zeus, who smote them with thunderbolts, and Heracles, who finished them off with arrows.
Second wave
Despite their initial bullying, the giants were defeated and the Olympian order was preserved but Gaea's anger did not subside. It is said that she was enraged and had intercourse with Tartarus and gave birth to even more vicious creature Typhoeus (Typhon), a hybrid monster with a terrifying upper body with a hundred dragon heads and lower body made of serpents. He was enormous in size, dwarfing mountains, and his mere presence caused natural upheavals such as violent storms and volcanic eruptions. When Typhoeus attacked heaven directly, the gods fled in terror, escaping to Egypt and transforming themselves into animals.
Only Zeus fought back, first from a distance using thunderbolts to strike the monster while being pursued. When they engaged in a close combat Zeus was first to strike the giant with adamantince sickle but was eventually overpowered by Typhoeus who wrestled his sickle and severed the sinews in god's hands and feet. Zeus was captured and brought to the Corycian cave in Cilicia where Delphyne, a she-dragon maiden, was tasked to guard him and his sinews, hidden in a bearskin, separately. The maiden, however, had failed to live up to the task as Hermes and Aegipan managed to steal back the sinews and secretly restored the god's strength. After Zeus regained his powers the cosmos witnessed the final battle between the two which took place in several locations. At Mount Nysa, the Fates tricked Typhoeus into eating fruit that made him believe he would gain strength, only to weaken him further. In Thrace at Mount Haemus, Typhoeus tried to fight back by hurling mountains, but Zeus’s thunderbolts caused the mountains to recoil and wound him. The giant tried to escape through the Sicilian Sea but Zeus cast Mount Etna upon him. The mountain, still active with fire and eruptions to this day, is said to be the result of the final strike from the king of the gods.
Rulership solidifed
The aftermath resulted in unquestionable authority and dominance of the Olympians over the Cosmos. No one would dare challenge Zeus and his allies after this war which had likely occurred during Heroic age (see Five ages of Man). While there is no direct confirmation by authors, apart that it happened after the Titans had already been defeated and imprisoned, there are a couple of clues. First is Heracles whose role was crucial to the victory and second is the head of Medusa being invoked by Athena, which means that Perseus had already completed his quest, both of which point to the heroic era. Regardless, the victory of the gods over the giants restored the balance in heaven and ensured the ongoing supremacy of the Olympian gods.