History of the Peloponnesian War

On the arrival of the men with Salaethus, the Athenians immediately put the latter to death, though he held out certain promises, and amongst others, that he would obtain the retreat of the Peloponnesians from Plataea (for it was still being besieged):

but respecting the former they deliberated what to do; and in their anger they determined to put to death, not only those that were there, but all the Mytilenaeans also that were of age; and to make slaves of the women and children. For they both urged against them [the aggravated character of] their revolt in other respects, namely, that they had executed it without being subject to their dominion, like the rest; and the fact of the Peloponnesian ships having dared to venture over to Ionia to assist them, contributed also no little to their wrath;

for they thought it was with no short premeditation that they had revolted. They sent therefore a trireme to Paches with intelligence of their resolution, and commanded him to despatch the Mytilenaeans as quickly as possible.

The next day they felt immediately a degree of repentance, and reflected that the resolution they had passed was a cruel and sweeping one, to put a whole city to the sword, instead of those who were guilty.

When the Mytilenaean ambassadors who were present, and those of the Athenians who co-operated with them, perceived this, they got the authorities to put the question again to the vote; and the more easily prevailed on them to do it, because they also saw plainly that the majority of the citizens wished some one to give them another opportunity of deliberating.

An assembly therefore being immediately summoned, different opinions were expressed on both sides; and Cleon, son of Cleaenetus, who had carried the former resolution, to put them to death, being on other subjects also the most violent of the citizens, and by far the most influential with the commons, at that time came forward again, and spoke as follows: