Thyestes killed Atreus. While Thyestes ruled Mycenae, the sons of Atreus, Agamemnon and Menelaus, were exiled to Sparta. There, King Tyndareus accepted them as the royalty that they were. Shortly after, he helped the brothers return to Mycenae to overthrow Thyestes, forcing him to live in Cytheria, where he died. As a token of good will and allegiance, King Tyndareus offered his daughters to Agamemnon and Menelaus as wives, Clytemnestra and Helen respectively. When Agamemnon left Mycenae for the Trojan War, Aegisthus seduced Agamemnon's wife, Clytemnestra, and the couple plotted to kill her husband upon his return. They succeeded, killing Agamemnon
History of Sparta them and defeated them. In 272 BC, Cleonymus of Sparta (who had been displaced as King by Areus), persuaded Pyrrhus to invade the Peloponnese. Pyrrhus laid siege to Sparta confident that he could take the city with ease, however, the Spartans, with even the women taking part in the defence, succeeded in beating off Pyrrhus' attacks. At this point Pyrrhus received an appeal from an opposition Argive faction, for backing against the pro-Gonatas ruler of Argos, and he withdrew from Sparta. In 264 BC, Sparta formed an alliance with Athens and Ptolomeic Egypt (along with a number smaller Greek cities)