(M503) On the third year, the Lacedaemonians, instead of ravaging Attica,
marched to the attack of Plataea. The inhabitants resolved to withstand the
whole force of the enemies. Archidemus, the Lacedaemonian general,
commenced the siege, defended only by four hundred native citizens and
eighty Athenians. So unskilled were the Greeks in the attack of fortified
cities, that the besiegers made no progress, and were obliged to resort to
blockade. A wall of circumvallation was built around the city, which was
now left to the operations of famine.

(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 Lacedaemonians 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 Lacedaemonians, under the persuasion of the Megarians, undertook
the bold enterprise of surprising the Piraeus, 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 Atheni