History of the Peloponnesian War

Thus then fared the party who were in Plataea.

The rest of the Thebans, who were to have joined them with all their forces while it was still night, in case those who had entered should be at all unsuccessful, on receiving on their march the tidings of what had happened, advanced to their succour.

Now Plataea is seventy stades distant from Thebes, and the rain which had fallen in the night made them proceed the slower; for the river Asopus was flowing with a full stream, and was not to be crossed easily.

So by marching through the rain, and having passed the river with difficulty, they arrived too late; as some of the men had been by this time slain, and others of them were kept alive as prisoners.