Atreus vowed to sacrifice the finest animal in his flock to Artemis; however, when he discovered a golden lamb in the flock, he reneged on the promise and hid the lamb away. At the same time his wife, Aerope, was having an affair with his brother, Thyestes. Aerope secretly gave the lamb to Thyestes, and Thyestes then got Atreus to agree that the possessor of the golden lamb should be king. Thyestes produced the lamb and seized the throne.
Atreus was determined to be king again. On the advice of Hermes, he got Thyestes to agree to yield the throne when the sun ran backwards in its course. Zeus then made the sun set in the east, and Atreus became king once more, banishing Thyestes for good measure.
Later, Atreus learned of his wife's adultery and decided to seek revenge for it. He invited Thyestes to return and be reconciled with him. He killed Thyestes' sons, cut them up, and cooked everything except their hands and feet. Then he served this meat at a banquet in Thyestes' honor. After Thyestes had finished eating, Atreus produced the hands and feet, taunted his brother with them, and banished him once more.
At this point, Thyestes was the one intent on revenge. An oracle advised him that his revenge would be successful if he fathered a son by his own daughter. He did so, and named the son Aegisthus. When Aegisthus grew to manhood, he killed Atreus and restored his father to the throne.
The curse continued long after Atreus' death. Thyestes was banished for a third and final time when Agamemnon, the son of Atreus, returned and seized the throne. Later on, Aegisthus seduced Agamemnon's wife, Clytemnestra, and the two of them murdered Agamemnon when he returned from the Trojan War. Agamemnon's children, Orestes and Electra, then plotted and carried out the murder of Aegisthus and Clytemnestra, thus continuing the curse into yet another generation.