Led by Zeus, the six siblings take up residence on Mt. Olympos and determine to overthrow their father Kronos. The Olympians are aided by Themis and her son Prometheus (according to the playwright Aeschylus; Hesiod knows a different mother) and by the Kyklopes and Hekatoncheires. The River Styx and her children also help. After the battle most of the Titans are imprisoned, at least temporarily. One exception is Atlas, who must hold up the sky (not the earth).

The victorious siblings divide their new conquest, and they do so in accordance with Indo-European tradition. Inheritance is for males only, and the inheritance is divided equally. So the three brothers draw lots to determine their portions. Zeus wins the sky, Poseidon the sea, and Hades the lower world. The ancestral "hearth and homestead" -- in this case Mt. Olympos and the earth -- are held in common.

After the defeat of the Titans, Zeus (either alone or with assistance) defeats several other menaces, thus consolidating his power.

Hesiod's description of the Titanomachy draws copiously on the imagery of the thunderstorm and other natural phenomena. The nature mythologists took the passage at face value, but the entire myth is also functional in justifying the "rightness" of the current world order.