Gr. Myth. a king of Mycenae and father of Agamemnon and Menelaus: to avenge the treachery of his brother, Thyestes, he kills Thyestes' sons and serves their flesh to him at a banquet
See Atreus in American Heritage Dictionary 4
(āˈtro͞osˌ, āˈtrē-əs)
noun Greek Mythology
A king of Mycenae, brother of Thyestes and father of Agamemnon and Menelaus.