History of the Peloponnesian War

At the end of the same summer, Aristeus, a Corinthian, Aneristus, Nicolaus, and Stratodemus, ambassadors of the Lacedaemonians, Timagoras, a Tegean, and Pollis, an Argive in a private capacity, being on their way to Asia, to obtain an interview with the king, if by any means they might prevail on him to supply money and join in the war, went first to Thrace, to Sitalces the son of Teres, wishing to persuade him, if they could, to withdraw from his alliance with the Athenians, and make an expedition against Potidaea, where was an armament of the Athenians besieging the place; and then, to proceed by his assistance to their destination across the Hellespont, to Pharnaces the son of Pharnabazus, who was to send them up the country to the king.

But some Athenian ambassadors, Learchus son of Callimachus, and Aminiades son of Philemon, happening to be with Sitalces, persuaded Sadocus his son, who had been made an Athenian citizen, to put the men into their hands, that they might not, by passing over to the king, do their best to injure [what was now] his own country.