Perseus was dispatched to kill Medusa, because he needed her head to fulfill a boastful gift to the King Polydectes, who held Perseus' mother, Danae, as his future queen against her will. Once Perseus beheaded Medusa with some help from Athena (who guided his hand) and Hermes, two monsters sprang from the drops of her blood.
There are supposed to be the children of Poseidon : one was Pegasus, the winged horse, and the other was the warrior Chrysaor (the father of the monster Geryon) with the golden sword. Perseus managed to escape the two other Gorgons thanks to the winged sandals of Hermes and the Helm of Hades (helmet of invisibility).
While Perseus was returning across the desert of Lybia, drops of blood fell on the ground from the severed head and were transformed by Gaia into venomous snakes of many kinds
The blood of the Gorgon had other special powers. The one that flowed on the right side had the power to reanimate the dead and was used by Erichthonius. The one that flows on the left side was a lethal poison and was kept by Athena who earned the nickname of “Instigator of wars”
The decapitated head of Medusa was used by Perseus to kill the sea monster Cetus. He then gave the head to Athena who fixed it in the middle of her Aegis or impenetrable shield and used it during the Troyan war. The Medusa shield of Athena was a favourite theme for armourers and sculptors in ancient times and in the Renaissance. image