Half-Olympian son of Poseidon by Eurynome; legal son of Glaucus, king of Corinth. Tamed Pegasus at the Peirene spring with Athena's golden bridle. Killed the Chimera (lion-goat-serpent fire-breathing monster) by mounting Pegasus and shooting from above — the foundational image of aerial warfare. Sent to his death by Proetus with the "Bellerophontic letter" (earliest mention of writing in Homer). In final hubris, attempted to fly Pegasus to Olympus; thrown off, fell into the Aleian plain crippled and god-rejected.