Theseus (Greek: Θησεύς) was a legenary king of Athens, son of Aethra, and fathered by Aegeus and Poseidon, with whom Aethra lay in one night. Theseus was a founder-hero, like Perseus, Cadmus or Heracles, all of whom battled and overcame foes that were identified with an archaic religious and social order. As Heracles was the Dorian hero, Theseus was the Ionian founding hero, considered by Athenians as their own great reformer. His name comes from the same root as θεσμός ("thesmos"), Greek for institution. He was responsible for the synoikismos ("dwelling together")—the political unification of Attica under Athens, represented in his journey of labours. Because he was the unifying king, Theseus built and occupied a palace on the fortress of the Acropolis that may have been similar to the palace excavated in Mycenae. Pausanias reports that after the synoikismos, Theseus established a cult of Aphrodite Pandemos ("Aphrodite of all the People") and Peitho on the southern slope of the Acropolis.