According to Greek mythological tradition the winged horse Pegasus was the son of Poseidon, sea and river god of the Greeks, equivalent to the Roman Neptune. The hero Bellerophon needed the untamed Pegasus to help him defeat the monster Chimera. Hence, while Pegasus was drinking at the spring Pirene in Corinth, Bellerophon caught him. Pegasus, startled, struck a rock with his hoof, creating the spring Hippocrene on Mount Helicon.