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, then his pride got the better of him and led to his downfall.
Bellerophon was the son of Eurynome, wife of Glaucus, by Poseidon. He was raised by Glaucus who thought Bellerophon was his own son. Considering both his fathers involvement with horses it is not surprising that he quested after Pegasus. After many failures he asked the seer Polyeidus for help.
Following Polyeidus instructions he spent the night at an alter to Athena. Here he had a dream of the goddess giving him a magical golden bridle. He awoke and found the bridle from the dream in his hands. He sensibly sacrificed to both Athena and Poseidon. This done he went to where Pegasus grazed and was able to bridle and ride 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 could take place he accidently killed a man, possibly one of his brothers, and was banished.
He went to King Proetus to be purified for his crime. This was done but, while staying as Proetus's house guest 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 wished 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.