Medusa was a monster, one of the Gorgon sisters and daughter of Phorkys and Keto, the children of Gaea (Earth) and Oceanus (Ocean). She had the face of an ugly woman with snakes instead of hair; anyone who looked into her eyes was immediately turned to stone. Her sisters were Sthenno and Euryale, but Medusa was the only mortal of the three.
She was originally a golden-haired, fair maiden, who, as a priestess of Athena, was devoted to a life of celibacy; however, after being wooed by Poseidon and falling for him, she forgot her vows and married him. For this offence, she was punished by the goddess in a most terrible manner. Each wavy lock of the beautiful hair that had charmed her husband was changed into a venomous snake; her once gentle, love-inspiring eyes turned into blood-shot, furious orbs, which excited fear and disgust in the mind of the onlooker; whilst her former roseate hue and milk-white skin assumed a loathsome greenish tinge.
Seeing herself transformed into such a repulsive creature, Medusa fled her home, never to return. Wandering about, abhorred, dreaded, and shunned by the rest of the world, she turned into a character worthy of her outer appearance. In her despair, she fled to Africa, where, while wandering restlessly from place to place, young snakes dropped from her hair; that is how, according to the ancient Greeks, Africa became a hotbed of venomous reptiles. With the curse of Athena upon her, she turned into stone whomever she gazed upon, till at last, after a life of nameless misery, deliverance came to her in the shape of death, at the hands of Perseus.