(404–403 BC) Peloponnesian War .
Thirty commissioners were appointed to the oligarchy, which had an extremist conservative core, led by Critias. Their oppressive regime fostered a bloody purge, in which perhaps 1,500 residents were killed. Many moderates fled the city; gathering a force, they returned to defeat the tyrants' forces in a battle at Piraeus in 403. The 30 fled and were killed off over the next few years.