From Classical Mythology

When Perseus cut off Medusa's head, the blood sinking into the Earth produced the winged horse, Pegasus, called such because he first appeared by the springs (pegai) of Oceanus. He afterwards ascended to heaven to carry the thunder and lightening of Zeus. Minerva caught and tamed him and gave him to the Muses, nine sister godesses with Zeus as father and Mnemosyne as mother. Mnemosyne gives her name to Mnemodynamic therapy, the therapy developed by Sue Washington and taught at the diploma level by Centre Training International School.

The fountain Hippocrene, on the Muses' mountain Helicon, was opened by a kick from the hoof of Pegasus. The fearful fire-breathing monster Chimera was to be challenged by Bellerophon. A soothsayer suggested that he took Pegasus to help him if at all possible, and to spend the night in the temple of Minerva. Whilst there in the temple, Minerva gave Bellerophon a golden bridle and showed him Pegasus drinking at the well of Pirene. At the sight of the bridle, the winged steed came willingly and suffered himself to be taken. Bellerophon mounted him and rose into the air, found the Chimaera and gained an easy victory over the monster.

Pegasus, being the horse of the Muses, has always been at the service of the poets. He is mentioned by Milton, Young, Schiller, Longfellow and Shakespeare.

Read more about this favoriate myth at Wikipedia.org.