The Gigantes attacked the Olympians in what is known as the Gigantomachy. Led on by Alcyoneus and Porphyrion, the Gigantes hoped to reach the top of Mount Olympus by stacking the mountain ranges of Thessaly, Pelion and Ossa, on top of each other. The Olympians called upon the aid of Heracles after a prophecy warned them that he was required to defeat the Gigante. Heracles slew not only Alcyoneus, but dealt the death blow to the Gigantes who has been wounded by the Olympians.
The Gigantes were Alcyoneus or Alkyonios, Athos, Clytias or Klytias, Enceladus, or Enkelados, Echion, and Pallas.