Aerope

In Greek mythology, Aërope was the wife of King Atreus of Mycenae. She had an affair with his brother, Thyestes.Atreus promised Artemis that he would sacrifice his best lamb to her. Upon finding a golden lamb, however, he gave it to Aërope to hide. She, in turn, gave the lamb to Thyestes, who agreed with Atreus that the person who possessed the golden lamb should become king of Mycenae. Atreus agreed and Thyestes seized the throne.
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[Greek heroic] The wife of Atreus. She committed adultery with his brother Thyestes and gave him the Golden Fleece through which Atreus would become the legal ruler of Mycene. Atreus prevented this.