History of the Peloponnesian War
Thucydides
Thucydides, Vol. 1-4. Smith, Charles Foster, translator. London and Cambridge, MA: Heinemann and Harvard University Press, 1919-1923.
When in this manner the senate had quietly withdrawn without making any opposition, and the citizens at large raised no disturbance but kept quiet, the Four Hundred entered the senate-chamber and for the present chose by lot prytanes[*](They were proceeding in the constitutional way. In the regular βουλὴ, the ten tribes took in turn the πρυτανεία or executive control of public affairs for one-tenth of the year (about thirty-five days). The prytanes would have been now forty in number instead of fifty as usual, as the new council consisted of forty from each tribe (Aristot. Ἀθ. Πολ., ch. xxxi.).) from their own number, and with respect to the gods observed all the usual rites of prayers and sacrifices as they assumed office. Afterwards, however, they departed widely from the democratic manner of administration —except that they did not recall the exiles, because of Alcibiades—and in general governed the city in a high-handed way.
A certain number of men, though not many, they put to death, for they thought it convenient to have them out of their way, while others they imprisoned, and also removed others from the city. Moreover, they made overtures to Agis, king of the Lacedaemonians, who was at Deceleia, saying that they wished to make peace and that it was only reasonable that he should be more ready to come to terms with them, having no longer to deal with the faithless democracy.
But Agis, thinking that the people would not in this way immediately surrender their ancient liberties, and that if they saw a large army of Lacedaemonians they would not remain quiet, and also not being quite sure at present that the Athenians were no longer in a state of disturbance, did not make a conciliatory response to those who had come as envoys from the Four Hundred. He sent instead for a large additional force from the Peloponnesus, and not long afterwards himself took the garrison at Deceleia together with the new arrivals and came down to the very walls of Athens, hoping either that the Athenians, being now in confusion, would more readily submit on terms pleasing to the Lacedaemonians, or else that, in consequence of the turmoil that would in all probability prevail both inside and outside the city, he would not fail at the first assault to capture the long walls at any rate owing to the absence of troops to defend them.
But when he came close and the Athenians made no move whatever from within the walls, but sending out the cavalry and a portion of the hoplites, light-armed troops and bowmen, shot down some of his men in consequence of their approaching too near and got possession of a number of arms and dead bodies, he at length recognized his mistake and led back his army.