Hercules is a demigod (half mortal and half god) who frees Prometheus from his chains on the mountain, where he has been imprisoned by the tyrant God Jupiter. In Roman mythology Hercules is the son of Jupiter and a mortal woman, Alcmene, and is a hero who performs many superhuman feats. It was common in epics and classical mythology for authors to include cameos by famous heroes in their stories; Shelley continues this tradition by including the famous figure of Hercules briefly in his narrative but expands very little on Hercules’s actions within the poem.