The most important post in the Athenian empire at this time was the island of Samos.  Here lay the greater part of their fleet, and it was from this headquarters that they sent out expeditions to recover the revolted cities of Ionia, and guarded those which they still retained, as, in spite of their great losses, they still possessed a fleet capable of holding its own against the Lacedaemonians.  They were in great fear of Tissaphernes and the Phoenician fleet of a hundred and fifty sail of triremes, which was said to be on the point of arriving, because if it really came all would be over with Athens.  Alkibiades, knowing this, sent a secret message to the Athenian leaders at Samos, holding out hopes of bringing Tissaphernes over to the Athenian side.  He would not, he said, do this to please the populace of Athens, because he could not trust them, but he would effect it if the nobility would, like brave gentlemen, put an end to the insolent behaviour of the lower orders, and would themselves undertake to save the city and empire of Athens.

All were eager to adopt the proposal of Alkibiades, except Phrynichus of the demos or township of Deirades, who suspected the real truth, that Alkibiades cared nothing about the form of government which might be established at Athens, but was seeking for some excuse for being restored to his native country, and thought, by his harsh language about the people, to ingratiate himself with the nobles.  He was, however, overruled; and, being now clearly marked as the personal enemy of Alkibiades, sent a secret message to Astyochus, the admiral of the Lacedaemonian fleet, bidding him beware of Alkibiades, who was playing a double game.  However, he met his match in perfidy.  Astyochus, desirous of gaining the favour of Tissaphernes, and seeing that Alkibiades had great influence with him, betrayed Phrynichus’s letter to them.  Alkibiades upon this at once sent persons to Samos to charge Phrynichus with this act of treason, and he, seeing that all men were shocked at what he had done, and were indignant with him, and being at his wit’s end, endeavoured to heal one mischief by another.  He sent a second letter to Astyochus, reproaching him for his betrayal of confidence, and promising that he would enable him to capture the fleet and camp of the Athenians.  However, the treachery of Phrynichus did no harm to the Athenians, because of the counter treachery of Astyochus, who communicated this letter also to Alkibiades.  Now Phrynichus, expecting a second charge of treason from Alkibiades, was beforehand with him, in announcing to the Athenians that the enemy were about to attack them, and advising them to keep near their ships, and to fortify their camp.[A] This they proceeded to do, when there came a second letter from Alkibiades, warning them against Phrynichus, who meditated betraying the harbour to the enemy.  This letter was not believed at the time, for men imagined that Alkibiades, who knew perfectly well all the movements and intentions of the enemy, was making use of that knowledge to destroy his personal enemy Phrynichus, by exciting an undeserved suspicion against him.  Yet, when afterwards Hermon, one of the Athenian horse-patrol, stabbed Phrynichus with his dagger in the market-place, the Athenians, after trying the case, decided that the deceased was guilty of treason, and crowned Hermon and his comrades with garlands.