Endius (gr.Ἔνδιος, Endios) of Sparta, son of Alcibiades, member of a family whose connexion with that of the Athenian Alcibiades had in a previous generation introduced into the latter this Lacedaemonian name. It is he apparently who was one of the three ambassadors sent by Sparta in 420 BC to dissuade Athens from the Argive alliance. They were chosen, says Thucydides, from the belief of their being acceptable to the Athenians, and possibly in particular with a view to conciliate his guest, Alcibiades, who probably made use of this very advantage in effecting the deception by which he defeated their purpose. He was elected ephor in the autumn of 413, the time of the Athenian disaster at Syracuse, and through him Alcibiades, now in inflicted on his country the severe blow of bringing the Lacedaemonians to the coast of Ionia, which otherwise would at any rate have been postphoned. Hs influence decided the government to lend its first succour to Chios; and when the blockade of their ships in Peiraeus seemed likely to put a stop to all operations, he again persuaded Endius and his colleagues to make the attempt. Thucydides says, that Alcibiades was his patrikos es ta malista xenos; so that probably it was with him that Alcibiades resided during his stay at Sparta. (Thuc. v. 44, viii. 6, 12.) To these facts we may venture to add from Diodorus (xiii. 52, 53) the further statement, that after the defeat at Cyzicus, 410 BC, he was sent from Sparta at the head of an embassy to Athens with proposals for peace of the fairest character, which were, however, through the influence of the presumptuous demagogue Gleophon, rejected. Endius, as the friend of Alcibiades, the victor of Cyzicus, would naturally be selected; and the account of Diodorus, with the exception of course of the oration he writes for Endius, may, notwithstanding the silence of Xenophon, be received as true in the main.