Zeus was the son of Kronos and Rhea. Because Kronos had heard a prophecy that one of his sons would overthrow him, he tried to swallow all his children as they were born. With the help of Gaia, Rhea tricked Kronos when Zeus was born by handing him a stone wrapped in a blanket. Kronos was in such a hurry that he swallowed the stone without realising.
Later, Zeus forced Kronos to regurgitate the stone (which became the Omphalos at Delphi, considered to be the centre of the world) followed by his brothers and sisters. Zeus and his brothers and sisters then overthrew Kronos and the Titans, and brought the rule of reason to the world. Zeus divided the world with his brothers Poseidon and Hades. He rules the sky with thunder and lightning, and they all share the Earth (Gaia).
Zeus has oracles at Dodona, home of the sacred oak, and Siwa in the Egyptian desert. At key moments Zeus holds up his golden scales to determine the outcome of events (fate). Remember what Homer says happened as Achilles chased Hector round Troy:
When they reached the springs for the fourth time, Father Zeus raised his golden scales and set the deaths of Achilles and horse-taming Hector in the balance, and lifted it on high. Down sank Hector’s lot towards Hades…