In Greek mythology Danaus, or Danaos ("sleeper"; Greek Δαναός), was the twin brother of Aegyptus and son of Achiroe and Belus, a mythical king of Egypt. The myth of Danaus is a foundation legend (or re-foundation legend) of Argos, one of the foremost Mycenaea] cities of the Peloponnesus. In Homer's Iliad, "Danaans" ("tribe of Danaus") and "Argives" commonly designate the Greek forces opposed to the Trojans in the Trojan War.