Catreus found Aerope in bed with a slave and handed her over to Nauplius to be drowned, but Nauplius spared Aerope's life. She then married Atreus, who was the king of Mycenae. Together, they had Agamemnon, Menelaus, and Anaxibia.
Atreus learned of Aerope's adultery with his brother Thyestes, and plotted revenge. He killed Thyestes' sons and cooked them, save their hands and feet. He tricked Thyestes into eating the flesh of his own sons and then taunted him with their hands and feet. Thyestes was forced into exile for eating the flesh of a human. Thyestes responded by asking an oracle what to do, who advised him to have a son by his daughter, Pelopia, who would then kill Atreus. However, when Aegisthus was first born, he was abandoned by his mother, who was ashamed of the incestuous act. A shepherd found the infant Aegisthus and gave him to Atreus, who raised him as his own son. Only as he entered adulthood did Thyestes reveal the truth to Aegisthus, that he was both father and grandfather to the boy. Aegisthus then killed Atreus.