History of the Peloponnesian War

"We should not have asked permission to make this address, if the Plataeans, on their part, had briefly answered the question put to them, and had not turned upon us and delivered an invective; while at the same time they made a long defence of themselves, beyond the limits of the present question, and on points that had never been the grounds of any charge, together with a panegyric for things which no one found fault with. But as it is, we must answer their accusations, and refute their self-praises; that neither our disgrace nor their reputation may assist them, but that you may hear the truth on both points, and so decide.

We quarrelled then with them in the first instance, because, on our settling Plataea at a later period than the rest of Boeotia, and some other places with it, of which we took possession after driving out their mixed population, these men did not think fit, as had been first arranged, to submit to our supremacy, but, apart from the rest of the Boeotians, offended against the principles of their fathers, and when they were being compelled to observe them, went over to the Athenians, in conjunction with whom they did us many injuries, for which they also suffered in return.