Prometheus Unbound, lyrical drama in four acts by Percy Bysshe Shelley, published in 1820. The work, considered Shelley’s masterpiece, was a reply to Aeschylus’s Prometheus Bound, in which the Titan Prometheus stole fire from heaven to give to mortals and was punished by Zeus (Jupiter). Shelley’s heroic Prometheus strikes against oppression as represented by a power-mad Jupiter. This brilliant but uneven work represented the culmination of the poet’s lyrical gifts and political thought.
Prometheus, tortured, is tempted to yield to Jupiter’s tyranny but instead forgives him. In this act, Shelley suggests, lies his salvation. Panthea and her sister Asia, symbol of ideal love, decide to free Prometheus by confronting Demogorgon, the volcanic power of the underworld, who vanquishes Jupiter in a violent eruption. Prometheus is reunited with his beloved Asia, and the liberation of human society is foretold. The last act, written months after the first three, describes this joyful transformation but warns that evil must be checked lest tyranny reign once more.