War of the Gods

Zeus claim of the Throne wouldn't be as easy as Cronos's one
had been. Cronos refused to acknowledge Zeus claim for the throne,
and refused to recognize his power. So Cromos called for
the other Titans to help him, and a 10-year long war between
the Titans and Zeus and his brothers and sisters,called
the "Titanomachy" started.

Zeus and his brothers and sisters entrenched themself on
Mount Olympus, the Titans and their children occupied
Mount Othrys in southern Greece. Zeus, being in the minority, took
a daring chance. He set the Cyclopes free, on the condition that they
would make weapons for him. they agreed, and made a Helmet of Invisibility
for Hades, a trident for Poseidon, and the ligtning for Zeus.
Next, Zeus gave the onehundred armed Giants their freedom back, who
turned out to be valuable allies. With their hundred arms, they
could very accurately throw giant rocks. Because Zeus did this,
he also gained Gaea's support, who had been trying for years
to free her children from their imprissonment. Gaea tried
to talk the Titans into acknowledging Zeus as the new Supreme God,
and although the wisest of them did, most did not and joined Cronos
in his figth against Zeus. The Titans made Atlas, one of Iapetus sons
their supreme commander, and under his command the battle started.

In the beginning, Zeus and his companions seemed to be winning, mostly
because of his lightning flashes, but Atlas and the Titans fought back
and resisted the attacks made by Zeus. In the end however, Zeus and
his forces gained the upper hand, and lay siege on Mount Othrys.
The three brothers, Zeus. Poseidon and Hades came up with a plan.
first, Hades, aided by his helmet, sneaked in to steal Cronos weapons.
After that, Poseidon would attack Cronos, allowing Zeus to
get a clear shot with his lightning bolts. Meanwhile, the Giants would
occupy the other Titans by attacking them with huge rocks.
they succeded, and the Titans were threw in the Tartarus,
where they were being guarded by the giants. Atles, their
commander, was forced to carry the skies on his shoulder.

According to some versions of the myth, Zeus later pardoned
the Titans, and send them away to the Elysium, an idyllic island
were they would  remain forever. Only Atlas wasn't forgiven,
and forced forever to carry the vault of heaven on his shoulders.
Before Zeus' control over the World is undisputed, he needs
to fight two more battles to secure his position as supreme God.
The first was called the "Giantomachy", a fierce battle he
had to fight against these monsters, who were born from the blood
of Uranus, spilled when Cronos castrated him.
Although Gaea has first joined forces with Zeus, his arrogant
behavior made her very angry, and she ask the Giants to overthrow
Zeus. They threw rocks and burning treetrunks against the Gods,
who were aided by their children Ares, Hermes, Apolla, Artemis and Athena.
Although they could injure the Giants, they were unable to kill them.
An oracle had foreseen that only a mortal could kill them, so Athena
asked Heracles to join forces with the Gods. With his help, the Olympic
Gods were finally able to kill the monsters.
Gaea's rage hadn't cooled down yet. She gave birth to the Typhon,
a monster with hundred dragonheads, snakes as legs and one hundred hands.
Zeus decided to face this enemy alone, thus starting a series of duels
fought so fierce that even the Titans, locked away in the
Tartarus shivered with fear.
Typhon managed to remove Zeus' tendon's, but Hermes found them
and placed them back into Zeus' body. After he had regained his strength,
he fought another battle with the Typhon and managed to kill it
under Mount Etna.
After gaining undisputed control, Zeus and his brothers
devided the world among them. Zeus would rule the Skies and
the Land, while Poseidon gained control over the Sea and Hades
over the Underworld. This marked the beginning of the thirth generation
of Gods, the Olympic Gods as we known them.