Megapenthes

In Greek mythology, Megapenthes (; Ancient Greek: Μεγαπένθης Megapénthēs means "great sorrow") was a king of Argos and the son of Proetus and exchanged kingdoms (Argos for Tiryns) with his cousin Perseus, whom he killed much later. He was the father of Argeus and possibly Anaxagoras (or else Anaxagoras was his grandson through Argeus). He also had a daughter Iphianeira, who married Melampus.