Bellerophon was a prince of Corinth, grandson of the cunning King Sisyphus and, according to some, son of the god Poseidon. He is the hero who tamed Pegasus, the winged horse born from Medusa's blood when Perseus cut off her head.
Winning Pegasus
Pegasus was free and wild, and no one could approach him. On a seer's advice, Bellerophon slept in Athena's temple, and in a dream the goddess handed him a golden bridle. When he woke the bridle was really beside him: he found Pegasus drinking at the Peirene spring in Corinth, slipped on the bit, and the horse let him ride.
The deadly letter
Exiled from Corinth for an accidental killing, Bellerophon took refuge with King Proetus of Tiryns. Queen Stheneboea fell in love with him and, rejected, falsely accused him to her husband. Proetus, unwilling to break the laws of hospitality by killing a guest, sent him to his father-in-law Iobates, king of Lycia, with a sealed letter asking for his death.
The Chimera
Iobates, also bound by hospitality, preferred to give Bellerophon deadly tasks. The first was to kill the Chimera, a monster ravaging Lycia: it had a lion's head, a goat's body and a serpent's tail, and breathed fire. Flying on Pegasus, beyond the reach of the flames, Bellerophon shot it with arrows, or in another version thrust a lead-tipped spear into its throat, which the monster's fire melted, choking it. Then he defeated the warlike Solymi and the Amazons and foiled an ambush by the king's warriors. Iobates realised the gods protected him and gave him his daughter and half his kingdom.
The fall
At the height of his glory, Bellerophon was seized by arrogance, what the Greeks called hybris: he tried to ride Pegasus up to Olympus, as if he were a god. Zeus sent a gadfly to sting the horse, which reared and threw him. Bellerophon fell to earth and spent the rest of his life lame or blind, wandering alone and hated by the gods. Pegasus, however, was welcomed on Olympus, where he carries Zeus's thunderbolts, and became a constellation.
See also monsters and myths in the stars.