Bellerophon's troubles begin in Corinth, where he accidentally kills a man, sometimes named as his own brother, and travels to Tiryns to be ritually purified by King Proetus. Proetus's wife Stheneboea, also called Anteia, propositions him, and when he refuses her she accuses him to her husband of attempting to assault her instead. Bound by guest friendship not to kill a man he has just purified, Proetus sends Bellerophon on to his father in law, Iobates, king of Lycia, carrying a sealed message that Bellerophon never reads, which asks Iobates to put the bearer to death.
Iobates, equally unwilling to kill a guest directly, instead sets him a sequence of tasks meant to finish him off less directly, starting with the Chimaera, a monster no one has managed to kill, and following with a campaign against the Solymi, a war against the Amazons, and an ambush by the best warriors in Lycia, which Bellerophon survives by killing every man sent against him. Convinced at last that the gods favor him, Iobates gives him half his kingdom and his daughter in marriage instead of the death the letter had requested.