Long Walls
Following their defeat in 404, the Athenians quickly regained some of their power and autonomy, and by 403 BC had overthrown the government that the Spartans had imposed on them. By 395 BC, the Athenians were strong enough to enter into the Corinthian War as co-belligerents with Argos, Corinth, and Thebes against Sparta. For the Athenians, the most significant event of this war was the rebuilding of the Long Walls. By 395 BC the rebuilding of the fortifications had begun and according to the Athenian admiral Conon, the walls had reached their final stages by 391 BC. In 394 BC, a Persian fleet under satrap Pharnabazus II and Conon decisively defeated the Spartan fleet at the Battle of Cnidus, and, following this victory, Pharnabazus sent Conon with his fleet to Athens, where it provided aid and protection as the Long Walls were rebuilt. Thus, by the end of the war, the Athenians had regained the immunity from land assault that the Spartans had taken from them at the end of the Peloponnesian War. The rebuilt walls stood for many years, unchallenged, and were never mentioned to have been incorporated in Athens' defense planning until after the 340s BC.