Now, according to the story, Bellerophon was given a bridle to tame the winged horse Pegasus, with which he would be able to slay the fearsome Chimera. If you recall the story of Perseus, you’ll know that Pegasus emerged from the neck of Medusa after Perseus beheaded her, which means that his story takes place after Perseus’ adventures.
With Pegasus, Bellerophon was able to defeat Chimera; vase-paintings show that this story was already well known by the early seventh century BC. Since he had survived all obstacles, Iobates decided to come clean and tell Bellerophon why he had sent him on such dangerous quests. Bellerophon was given half the kingdom and Iobates’ daughter’s hand in marriage, but he also wanted revenge on Iobates’ wife.
Bellerophon flew with Pegasus to Tiryns and told Proetus’ wife that he loved her and to climb on the creature’s back. She did so. Once they were over the sea, Bellerophon told her to lean over at which point he either pushed her off or caused her to slide off Pegasus’ back. She plummeted into the sea and drowned.
Bellerophon probably lived for some time in Lycia, where he fathered a number of children. Eventually, though, he decided to fly with Pegasus up Mount Olympus to see how the gods lived. Zeus didn’t like this display of arrogance and sent an insect to sting the horse as he and Bellerophon flew up the mountainside. Pegasus reared in mid-air and Bellerophon fell off. The hero spent the remainder of his life as a broken man, while Pegasus was allowed to reach the summit and live among the Olympian deities.
Like Perseus, Bellerophon made a name as a monster-slayer and the two stories became conflated already in the course of the Classical period. Perseus was a more popular hero and so he eventually came to be associated with Pegasus, probably mounting the creature to escape from the island of the gorgons.