Pegasus in Greek mythology, a winged horse which arose with Chrysaor from the blood of the Gorgon Medusa, when she was slain by Perseus. He is said to have received his name because he first made his appearance beside the springs (πηγαί) of Oceanus. He afterwards ascended to heaven, and was believed to carry the thunder and lightning of Zeus. According to later authors, however, he was the horse of Eos. The myth concerning Pegasus is interwoven with that of the victory of Bellerophon over the Chimaera. Bellerophon had in vain sought to catch Pegasus for his combat with this monster, but was advised by the seer Polyidos of Corinth to sleep in the temple of Minerva, and the goddess appearing to him in his sleep gave him a golden bridle and certain instructions, upon which he acted, and made use of Pegasus in his combat with the Chimaera, the Amazons, and the Solymi. Pegasus is also spoken of in modern times as the horse of the Muses, which, however, he was not. The ancient legend on this subject is that the nine Muses and the nine daughters of Pieros engaged in a competition in singing by Helicon, and everything was motionless to hear their song, save Helicon, which rose ever higher and higher in its delight, when Pegasus put a stop to this with a kick of his hoof, and from the point arose Hippocrene, the inspiring spring of the Muses. But that Pegasus is the horse of the Muses is entirely a modern idea, being first found in the Orlando Innamorato of Boiardo.