[Sidenote: B. C. 411.] =195.= Though convinced that they had been cheated by Alcibiades, they had now gone too far to recede from the proposed revolution. Pisander, with five of his colleagues, returned to Athens, while the rest went about among the allies to establish oligarchies. At Athens the old offices were abolished, and a Council of Four Hundred, chiefly self-elected, held power for four months. By the aid of the army at Samos, a counter-revolution was effected, and the leaders of the oligarchy were accused of treason for their dealings with the Spartans. Most of them fled; but two, Ar´cheptol´emus and Antiphon, were tried and executed. =196.= The remainder of the Peloponnesian war was wholly maritime, and its scene of operations was on the coast of Asia Minor. The Spartans, by long practice and close collision with their great rivals, had become nearly equal to the Athenians in naval skill. Their attention to this arm of the service was shown by the yearly appointment of the _navarchus_, an officer whose power, while it lasted, was even greater than that of the kings, for he was above the control of the ephors. [Sidenote: B. C. 411.] =197.= Min´darus, the Spartan commander at Miletus, becoming disgusted with the fickle policy of Tissaphernes, set sail for the Hellespont, hoping to find the other satrap more constant to the Spartan alliance. He was followed by an Athenian fleet, under Thrasyl´lus, which, though less numerous than his own, inflicted upon him a severe defeat in the strait between Sestus and Abydus. Mindarus now sent for the allied fleet at Eubœa, but in passing Mount Athos it was overtaken by a violent storm, and wholly destroyed. The Athenians followed up their advantage by the capture of Cyz´icus, which had revolted from them; and, a few weeks later, gained another great battle near Abydus, by the timely aid of Alcibiades. =198.= In the spring of 410, Mindarus was besieging Cyzicus, and the Athenians determined to relieve it. They passed up the Hellespont in the night, and assembled at Proconnesus. Alcibiades moved toward Cyzicus with his division of the fleet, and succeeded in enticing Mindarus to a distance from the harbor, while the other two divisions stole between him and the city, and thus cut off his retreat. A battle ensued, in which Mindarus was slain, the Spartans and their Persian allies routed, and the entire Peloponnesian fleet captured, except the Syracusan ships, which Hermocrates caused to be burnt. =199.= This victory restored to the Athenians the control of the Propontis and the trade of the Euxine. Ships laden with corn now entered Piræus, bearing relief to the hungry poor, and discouragement to King Agis, who still held the heights of Decelea, in the vain hope of starving the city into surrender.