It all started on Mount Olympus were Gaea, the earth goddess fell in love with Uranus, The sky god and had 12 children known as the titans.
One day their most bravest son Chronos fought his father with his siblings. Uranus realizing that he could not defeat them he ran away
After overthrowing his father Chronos married the powerful goddess Rhea.
Chronos feared that his children would overthrow him so he decided to eat all of his children. After Chronos ate their fifth child Rhea decided that when the next child is born she would name him Zeus and give Chronos  a rock to swallow instead. She sent Zeus to live with the nymths