The Giants were as tall as mountains and so strong as to be unbeatable. While Zeus was establishing himself, the Earth gave birth to a new, monstrous set of gods, the Giants, which were fathered by the Sky. Even after Zeus took charge, succeeding generations and different races of gods still competed for control of Olympus. Kronos was father to Zeus and the Olympians, and he, too, was overthrown by his son. Ouranos was the king of the first generation of gods, but he was overthrown by Kronos, who was his son. Zeus wasn't always the king of the Greek gods.
