In Greek mythology, Porthaon (Ancient Greek: Πορθάων, genitive Πορθάονος), sometimes referred to as Parthaon or Portheus (seems related to the verb portheō and perthō, "destroy'[1]), was a king of Calydon and son of Agenor or Ares[2] by Epicaste and thus brother of Demonice (also known as Demodice)[3] and possibly Thestius.[4]
Porthaon was the husband of Euryte, daughter of Hippodamas, who became the mother of his children, Oeneus, Agrius, Alcathous, Melas, Leucopeus and Sterope. In some account, his wife Laothoe[5] bore him three daughters, Sterope, Eurythemiste and Stratonice.[6] By an unnamed servant, Porthaon was the father of the Argonaut Laocoön.[7] Dia, the consort of his son Agrius was also called his daughter.[8]