Medusa part of their religion. Medusa was beheaded by the hero Perseus, who thereafter used her head, which retained its ability to turn onlookers to stone, as a weapon until he gave it to the goddess Athena to place on her shield. In classical antiquity the image of the head of Medusa appeared in the evil-averting device known as the "Gorgoneion". The three Gorgon sisters—Medusa, Stheno, and Euryale—were all children of the ancient marine deities Phorcys (or "Phorkys") and his sister Ceto (or "Keto"), chthonic monsters from an archaic world. Their genealogy is shared with other sisters, the Graeae, as in
Greek mythology the existence of this corpus of data is a strong indication that many elements of Greek mythology have strong factual and historical roots. Mythical narration plays an important role in nearly every genre of Greek literature. Nevertheless, the only general mythographical handbook to survive from Greek antiquity was the "Library" of Pseudo-Apollodorus. This work attempts to reconcile the contradictory tales of the poets and provides a grand summary of traditional Greek mythology and heroic legends. Apollodorus of Athens lived from to and wrote on many of these topics. His writings may have formed the basis for the collection; however the