Bellerophon provides a lesson in the proper relationship between a mortal hero and the gods. When he was young he honored the gods and won their favor, but eventually his pride got the better of him and led to his downfall.
Bellerophon was the son of Poseidon and Eurynome, wife of Glaucus. He was raised by Glaucus who thought Bellerophon was his own son. Considering that both Poseidon and Glaucus were interested in horses, it is not surprising that Bellerophon quested after Pegasus. After many failures, he asked the seer Polyeidus for help.
Following Polyeidus' instructions, he spent the night in a temple of Athena. There, he had a dream that the goddess offered him a magical, golden bridle. He awoke and found the bridle he dreamt about in his hands. He sensibly made a sacrifice to both Athena and Poseidon. Afterwards, he went to the meadow Pegasus was grazing at, and was able to bridle and tame the horse without difficulty. Triumphant in his success, he went to King Pittheus and received permission to marry his daughter Aethra. However, before the marriage, he accidentally killed a man, possibly one of his brothers, and was banished.
He went to King Proetus to be excused for his crime. The king pardoned him, but during his stay at Proetus's house, the King's wife, Stheneboea, attempted to seduce him. As an honorable man Bellerophon rejected her advances. This infuriated Stheneboea who then falsely accused him of attempting to seduce her.
Greatly upset, Proetus wanted to be rid of Bellerophon without having to accuse him publicly. He was also concerned about harming a house guest, as this was an offence to the gods. So, he sent Bellerophon to deliver a sealed message to his wife's father, King Iobates.
Arriving on Pegasus, Bellerophon was warmly received and settled in as Iobates' house guest. Iobates unsealed and read the message thus learning of Stheneboea's accusations against Bellerophon. This left Iobates in the same predicament of acting against a guest that had troubled Proetus.
Iobates' solution was to ask Bellerophon to undertake a series of heroic, but deadly tasks. However, Bellerophon's courage and skill as an archer, combined with Pegasus' help, allowed him to prevail. In addition, his parentage, his sacrifices, and his acts of honour gave him the favour of the gods. His first task was to kill the terrible Chimaera. Succeeding, he was sent to conquer the neighbouring Solymi tribe, which was Iobates' traditional enemy. When he defeated them, the King sent him to fight the Amazons. He was again victorious. In desperation, Iobates led an ambush against Bellerophon using his entire army; the army was killed to the last man.
At this point, Iobates had the wisdom to notice that something was very wrong. He realized that the gods favoured Bellerophon and that this favor would not have been given to a dishonorable house guest. Iobates succeed in making amends by giving Bellerophon half his kingdom, including the best farmlands and his daughter Philonoe in marriage.
There are two stories concerning the fate of Stheneboea. One says that Bellerophon extracted revenge by taking her for a ride on Pegasus, then shoving her off to fall to her death. In the other version, Stheneboea hears that Bellerophon has married her sister. She knows that this means her slander would be revealed and chose to kill herself.
It appeared that Bellerophon would live happily ever after. His glorious deeds were widely sung. He was happily married. Philonoe bore him two sons, Isander and Hippolochus, and two daughters, Laodameia and Deidameia. As a king his subjects loved and honored him.
However, this was not enough for Bellerophon. In his arrogance, he decided that he could ride Pegasus to Mount Olympus and visit the gods. Zeus quickly put an end to his trip by sending the gadfly to sting Pegasus and dismount Bellerophon. He survived his fall, but was crippled. He spent the rest of his life wandering the earth. No man would help him because of his offense to the gods. He died alone with no one to record his fate.