Perseus the legendary founder of Mycenae and of the Perseid dynasty there, was the first of the mythic heroes of Greek mythology whose exploits in defeating various archaic monsters provided the founding myths of the twelve Olympians. Perseus was the Greek hero who killed Medusa and claimed Andromeda, having rescued her from a sea monster.

Perseus was the son of Zeus and Danae. Danae's father, King Acrisius, set Danae and her son adrift on the sea because of prophecy that Perseus would him. The two were taken in by Polydectes, the king of Seriphus. Polydectes later conceived a passion for Danae, but was unable to force his attentions on her because Perseus had grown into a redoubtable protector. To get rid of Perseus, Polydectes sent him on a quest to bring back the head of the Gorgon Medusa, a snake haired maiden who turned all who saw her into stone.

Perseus accomplished his quest with the help of Hermes &Athena. He went first to the Gorgons' sisters, the Graeae, who had only one eye and one tooth which they shared among themselves. Perseus took the eye and the tooth and agreed to give them back only if the Graeae helped him in his quest. They helped him acquire a pair of winged sandals, a wallet or satchel and the cap of Hades; the sandals enabled him to fly, the satchel was to carry the Gorgon’s head, and the cap conferred invisibility on its wearer. Wearing the cap, he approached Medusa, looking only at her reflection in his shield, and cut off her head.

As he flew back over Africa on his way home, he en counted Atlas; in the course of a struggle, he used the Gorgon's head to turn Atlas to stone (thereby) forming the Atlas Mountains. He also dripped blood from the head onto the sands of African desert, giving birth to the deadly vipers of that region. Later in the journey he saw the maiden Andromeda chained naked to a rock by the sea as a sacrifice to a sea monster. He fell in love with her and bargained with her father, Cepheus, for her hand in marriage if he killed the monster. He succeed in slaying the beast, but at the wedding feast Phineus, a jilted suitor of Andromeda, angrily demanded the bride. In the battle which followed, Perseus used Medusa's head to turn Phineus and followers into stone.