"The Hero with a Thousand Faces" (first published in 1949) is a work of comparative mythology by Joseph Campbell, in which the author discusses his theory of the mythological structure of the journey of the archetypal hero found in world myths.

Since the publication of "The Hero with a Thousand Faces", Campbell's theory has been consciously applied by a wide variety of modern writers and artists. Filmmaker George Lucas acknowledged Campbell's theory in mythology, and its influence on the Star Wars films.

Campbell explores the theory that mythological narratives frequently share a fundamental structure. The similarities of these myths brought Campbell to write his book in which he details the structure of the monomyth. He calls the motif of the archetypal narrative, "the hero's adventure". In a well-known quote from the introduction to "The Hero with a Thousand Faces", Campbell summarizes the monomyth:

"A hero ventures forth from the world of common day into a region of supernatural wonder: fabulous forces are there encountered and a decisive victory is won: the hero comes back from this mysterious adventure with the power to bestow boons on his fellow man".

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