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.
Hippocrates was thus exhorting his men and had got as far as the centre of the army, but no further, when the Boeotians, after they too had again been briefly harangued by Pagondas, raised the paean and came on from the hill. And the Athenians also advanced against them and met them on a run.
The extremities of the line on either side never came to close quarters, for both had the same difficulty-they were hindered by swollen torrents. The rest were engaged in stubborn conflict, with shield pressed against shield.
And the Boeotian left, as far as the centre, was worsted by the Athenians, who pressed hard upon all the rest in that quarter, and especially upon the Thespians. For when they saw that the ranks on either side had given way and that they were surrounded, those of the Thespians who perished were cut down fighting hand to hand.
And some also of the Athenians, getting into confusion owing to their surrounding the enemy, mistook and killed one another. Here, then, the Boeotians were defeated and fled to the part of their army which was still fighting;
but the right wing, where the Thebans were, had the better of the Athenians, and pushing them back step by step at first followed after them. It happened also that Pagondas, when their left was in distress, sent two squadrons of cavalry round the hill from a point out of sight, and when these suddenly appeared, the victorious wing of the Athenians, thinking that another army was coming on, was thrown into a panic.