History of the Peloponnesian War

Afterwards, when the Peloponnesian allies had been dismissed to their several cities, Brasidas went back to Corinth and began preparations for the expedition to Thrace, whither he had originally been bound.

But when the Athenians also returned home, all the Megarians who had been most implicated in the negotiations with the Athenians, knowing that they had been detected, immediately withdrew secretly from the city, while the rest, communicating with the friends of the exiles, brought them back from Pegae, after first binding them on their oath by strong pledges not to harbour ill-will, but to consult for the best interests of the city.

But as soon as these men attained office and had made an inspection of arms, separating the companies they selected about one hundred of their personal enemies and of those who seemed to have had the largest part in the negotiations with the Athenians, and compelling the popular assembly to take an open vote concerning these, when they had been condemned, slew them, and established an extreme oligarchy in the city.

And there was never a change of government, effected by so small a number of men through the triumph of a faction, that lasted so long.