Alcibiades (/ˌælsɪˈbaɪədiːz/; Ancient Greek: Ἀλκιβιάδης; c.450–404 BC) was an Athenian statesman and general. The last of the Alcmaeonidae, he played a major role in the second half of the Peloponnesian War as a strategic advisor, military commander, and politician, but subsequently fell from prominence.
During the course of the Peloponnesian War, Alcibiades changed his political allegiance several times. In his native Athens in the early 410s BC, he advocated an aggressive foreign policy and was a prominent proponent of the Sicilian Expedition. After his political enemies brought charges of sacrilege against him, he fled to Sparta, where he served as a strategic adviser, proposing or supervising several major campaigns against Athens. However, Alcibiades made powerful enemies in Sparta too, and defected to Persia. There he served as an adviser to the satrap Tissaphernes until Athenian political allies brought about his recall. He served as an Athenian general (strategos) for several years, but enemies eventually succeeded in exiling him a second time. He took refuge in Persian territory and was eventually assassinated, reportedly at the instigation of Sparta.