http://www.idbsu.edu/courses/hy101/peloponn/16.htm

Final Defeat

 Such an expedition is always tricky. The crews have to put to shore, leaving the fleet under-manned. It was imperative at such a time to know the location of the enemy and to keep a sharp eye for ships. This was not done.

 The Athenians were surprised by the Corinthians and Spartans, and the fleet was almost completely destroyed. Athens lost the better part of her 180 ships, while the 200 Spartan ships survived the battle in good shape.

The Athenian treasury was empty. There could be no heroic recovery as there had been after the disaster in Sicily. And, without the fleet, the strategy of Pericles failed at last.

 A Spartan army invaded Attica in 404. After a short resistance, Athens was forced to surrender.

 The terms of the peace were harsh. Sparta demanded the destruction of the walls around the Piraeus, as well as the Long Walls running from Athens to the port. The citizens of Athens themselves were forced to pull down their own handiwork.

 The Athenian war fleet was reduced to twelve ships--barely enough to protect her shipping. Athens was also forced to become a junior ally of Sparta, and so lost the right to form her own foreign policy.

 Sparta of course blamed much of the behavior of Athens on her form of government. The exiled aristocrats were restored to power, and the entire government was placed in the hands of a committe of thirty. These instituted reprisals against their enemies so bloody (about 1,500 political murders in the space of eight months) that they earned for themselves the name of the Thirty Tyrants. They in fact behaved so outrageously that a milder demoracy was restored in 403, but Athens was still subject to Sparta.  

History of Western Civilization