Megapenthes (son of Proetus)In Greek mythology, Megapenthes was a king of Argos.FamilyMegapenthes was the son and successor of Proetus and father of either Argeus or Anaxagoras. He also had a daughter Iphianeira, who married Melampus.MythologyMegapenthes exchanged kingdoms with his cousin Perseus whom he killed much later.