History of the Peloponnesian War

Afterwards Brasidas, having dismissed his confederates to their several cities, went himself to Corinth in pursuit of his former purpose to levy an army for Thrace.

Now the Megareans that were in the city (when the Athenians also were gone home), all that had chief hand in the practice with the Athenians, knowing themselves discovered, presently slipt away; but the rest, after they had conferred with the friends of the outlaws, recalled them from Pegae, upon great oaths administered unto them no more to remember former quarrels, but to give the city their best advice.

These, when they came into office, took a view of the arms, and disposing bands of soldiers in divers quarters of the city, picked out of their enemies and of those that seemed most to have co-operated in the treason with the Athenians, about a hundred persons; and having constrained the people to give their sentence upon them openly, when they were condemned slew them, and established in the city the estate almost of an oligarchy.

And this change of government, made by a few upon sedition, did nevertheless continue for a long time after.