Defeat For Athens
For many city states of the age, the failure in Sicily would have ended their war. However, Athens managed to regroup and ultimately gain parity with Sparta regarding naval power. Members of the Athenian empire were encouraged to revolt after Sicily and Sparta had the problem of having too many potential allies; each with their demands. Despite having the upper hand, Sparta suffered a couple of defeats in 412 BC as it attempted a naval expedition to Chios followed by Lesbos.
At this point, there were apparently revolts all over Greece with states such as Chios, Teos, and Miletus launching uprisings. Sparta forged an alliance with Persia, and by the winter of 412/11, it was apparent that Athens had lost naval superiority. This was demonstrated when Athens lost a minor naval battle at Cnidus; a second fleet arrived but neglected to engage for fear of another loss.
Athens was in political turmoil by 411 BC. Democracy was replaced by an oligarchy which was ultimately replaced by the regime of the Five Thousand. Despite this, Athens was in the midst of a remarkable turnaround in the war. Victories in naval battles at Cynossema in 411 BC and Cyzicus in 410 BC appeared to put Athens in control; the latter victory resulted in the return to democracy in Athens as the Five Thousand’s rule ended.
After yet another victory at the Battle of Megara (a land battle) in 409 BC, Athens once again went on the offensive. It captured various territories in 408 BC as it looked to defeat its bitter rival. In 407 BC, Sparta made a fateful decision; it appointed Lysander as the admiral of its fleet in the Aegean. He turned out to be an excellent commander and boosted the quality of the Peloponnesian fleet to the point where it won Sparta the war. Another critical event occurred that year; Cyrus the Younger, a prominent Persian prince, was made satrap of several regions and made it clear that he wished to support Sparta.
Lysander was replaced by Callicratidas, but when the latter was killed in the Battle of the Arginusae Islands in 406 BC, Lysander assumed command once again. The decisive battle of the Second Peloponnesian War occurred at Aegospotami in 405 BC where Lysander annihilated his poorly organized opponents. All but 10 of the 180 Athenian ships were captured on the nearby beach, and 3,000 men were executed. The Delian League had no fleet and was forced to disband while Athens came under siege. It accepted harsh peace terms; for example, Athens was not allowed a fleet of more than 12 ships.
Defeat in the Second Peloponnesian War meant that Athens would never again threaten to dominate Greece. Sparta became the dominant power, but its success was short-lived as its territorial ambitions led to the start of the Corinthian Wars in 396 BC. Defeat to Thebes in 371 BC at the Battle of Leuctra kept Sparta in check. The real winner of this lengthy conflict was probably Macedonia. The weakened Greek city-states were no match for Philip II when he launched his invasion in the 350s BC.