(M504) At the same time the siege was pressed, an Athenian armament was sent to Thrace, which was defeated; but in the western part of Greece the Athenian arms were more successful. The Spartans and their allies suffered a repulse at Stratus, and their fleet was defeated by Phormio, the Athenian admiral. Nothing could exceed the rage of the Lacedæmonians at these two disasters. They collected a still larger fleet, and were again defeated with severe loss near Naupactus, by inferior forces. But the defeated Lacedæmonians, under the persuasion of the Megarians, undertook the bold enterprise of surprising the Piræus, during the absence of the Athenian fleet; but the courage of the assailants failed at the critical hour, and the port of Athens was saved. The Athenians then had the precaution to extend a chain across the mouth of the harbor, to guard against such surprises in the future. (M505) Athens, during the summer, had secured the alliance of the Odrysians, a barbarous but powerful nation in Thrace. Their king, Sitalces, with an army of fifteen thousand men, attacked Perdiccas, the king of Macedonia, and overran his country, and only retired from the severity of the season and the want of Athenian co-operation. Such were the chief enterprises and events of the third campaign, and Athens was still powerful and unhumbled. (M506) The fourth year of the war was marked by a renewed invasion of Attica, without any other results than such as had happened before. But it was a more serious calamity to the Athenians to learn that Mitylene and most of Lesbos had revolted—one of the most powerful of the Athenian allies. Nothing was left to Athens but to subjugate the city. A large force was sent for this purpose, but the inhabitants of Mitylene appealed to the Spartans for aid, and prepared for a vigorous resistance. But the treasures of Athens were now nearly consumed, and the Athenians were obliged to resort to contributions to force the siege, which they did with vigor. The Lacedæmonians promised succor, and the Mitylenæans held out till their provisions were exhausted, when they surrendered to the Athenians. The Lacedæmonians advanced to relieve their allies, but were too late. The Athenian admiral pursued them, and they returned to the Peloponnesus without having done any thing. Paches, the Athenian general, sent home one thousand Mitylenæan prisoners, while it was decreed to slaughter the whole remaining population—about six thousand—able to carry arms, and makes slaves of the women and children. This severe measure was prompted by Cleon. But the Athenians repented, and a second decree of the assembly, through the influence of Diodotus, prevented the barbarous revenge; but the Athenians put to death the prisoners which Paches had sent, razed the fortifications of Mitylene, took possession of all her ships of war, and confiscated all the land of the island except that which belonged to one town that had been faithful. So severe was ancient