Demophon was a Greek hero who ruled Athens alongside his brother Acamas. Demophon and Acamas were sons of Theseus, the most important of all Athenian heroes; their mother, in many sources, was Theseus’ wife Phaedra, though some made Demophon the son of a woman named Iope.
Demophon and Acamas fought bravely in the Trojan War. After the city was sacked, they rescued their grandmother Aethra, who had been brought to Troy as Helen’s handmaiden. The brothers then returned home to Athens and reclaimed their father’s old kingdom, which had usurped years before by Menestheus. During their rule, they protected the Heraclidae (Heracles’ descendants) from Eurystheus.
In one story, either Demophon or Acamas married the Thracian princess Phyllis during their journey back to Greece. There are different versions of the story, but all agree that Demophon (or Acamas) eventually left Phyllis—an act that resulted in the death of one or both lovers.