History of the Peloponnesian War

The Plataeans, when they perceived that the Thebans were already entered and had surprised the city, through fear and opinion that more were entered than indeed were (for they could not see them in the night), came to composition and accepting the condition rested quiet, and the rather, for that they had yet done no man harm.

But whilst that these things were treating, they observed that the Thebans were not many and thought that if they should set upon them, they might easily have the victory. For the Plataean commons were not willing to have revolted from the Athenians.

Wherefore it was thought fit to undertake the matter, and they united themselves by digging through the common walls between house and house that they might not be discovered as they passed the streets. They also placed carts in the streets without the cattle that drew them to serve them instead of a wall, and every other thing they put in readiness as they severally seemed necessary for the present enterprise.

When all things according to their means were ready, they marched from their houses towards the enemies, taking their time whilst it was yet night and a little before the break of day because they would not have to charge them when they should be emboldened by the light and on equal terms, but when they should by night be terrified and inferior to them in knowledge of the places of the city. So they forthwith set upon them and came quickly up to hand strokes.