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 or expert advice. By 408 the Great King had perceived that the agreement with the Spartans was not being implemented. He sent his brother, Cyrus the younger, to relieve Tissaphernes of his command of Lydia. Tissaphernes was pushed aside to the governorship of Caria. Exposed, Alcibiades departed for Athens in 407. In his place Sparta sent an agent of similar capabilities, a friend of King Agis, Lysander, who as "a diplomat and organizer ... was almost flawless, unless we count arrogance, dishonesty, unscrupulousness and brutality as flaws." He and Cyrus got along well. Upgrade of the Spartan fleet proceeded rapidly.