Atreus and Thyestes.

Sons of Pelops, Atreus and Thyestes engaged in a bitter and endless struggle for control of Mycenae, promised by an oracle to an unspecified son. The right of dominion was conferred by a golden-fleeced ram, given to Atreus by Hermes, but Thyestes gained possession of the ram through his adulterous affair with Atreus’s wife, Aërope. With the help of Zeus and Eris, Atreus regained Mycenae and banished Thyestes.
In an extraordinary act of revenge, Atreus then invited his brother to a banquet, ostensibly as a gesture of reconciliation. Included on the menu was the flesh of Thyestes’ sons, which Thyestes unsuspectingly consumed. When he learned what he had done, he went again into exile (or was banished), cursing Atreus’s name for eternity. This curse on the House of Atreus was borne out in the fates of his descendants, especially that of his son Agamemnon.
According to Apoliodorus and Hyginus, Thyestes later had an incestuous affair with his own daughter, Pelopia, on the advice of an oracle. Pregnant, she married Atreus and subsequently gave birth to a son, Aegisthus. As a child, Aegisthus was ordered by Atreus to kill Thyestes, but learning that Thyestes was his father, the boy helped to slay Atreus.
The story of Atreus and Thyestes was popular in ancient literature and has remained so in postclassi-cal tragedies and tragic operas.

Classical Sources. Aeschylus, Agamemnon 1583—1602. Euripides, Thyestes. Ennius, Thyestes. Accius, Atreus. Varius Rufus, Thyestes. Apoliodorus, Biblioteca 2.4.6, E2.10—15. Seneca, Thyestes. Hyginus, Fabulae 83, 86, 88.