The Graeae ("old women" or "gray ones", alternatively spelled Graiai, Graiae, Graii ), were three sisters, one of several trinities of archaic goddesses in Greek mythology.
Family
The Graeae were daughters of Phorcys, one aspect of the "old man of the sea," and Ceto, and thus were among the Phorcydes, all of which were archaic beings either of the sea or chthonic deities. Hesiod reports their names as Deino ("dread", the dreadful anticipation of horror), Enyo ("horror" the "waster of cities" who had an identity separate from this sisterhood) and Pemphredo ("alarm") (Theogony, 270 - 74; also Apollodorus,ii.4.2; sometimes spelled Porphredo). Her other sisters were female monsters known as the Gorgons. The Gorgons, who the Graea guarded, were Euryale, Sthenno, and Medusa.
The Graeae can be compared with the three spinners of Destiny (the Moirae), the northern European Norns, or the Baltic goddess Laima and her two sisters.
Description
They look like old ladies, born old, with long gray hair, and shaped like swans. Other tales pretend that the Graes shared one eye and one tooth among one another and were believed to be hideous looking creatures.
Role
They dwelt near the entrance to the Underworld, and were the guardians of the Gorgons. They protected the nymphs, who protected Hades' invisible helmet and a pair of winged sandals belonging to Hermes. They also oversaw the safety of the shield of Athena.
Story
In one mythological story King Polydectes sent Perseus off to bring back the head of Medusa, one of the Gorgons. Since Perseus needed information on where to find Medusa, he went to Deino and the other two Graeae. As the sisters were passing their eye between them, Perseus snatched the Graea's only eye and said that he would not return the eye until they told him where the Gorgon's lived. In desperation the Graea told Perseus where they lived, which further led him to finding Hades invisible helmet and winged shoes. Perseus was able to destroy Medusa because of his invisibility and his ability to fly.