History of the Peloponnesian War

In this part of the field the Boeotians were beaten, and retreated upon the troops still fighting; but the right, where the Thebans were, got the better of the Athenians and shoved them further and further back, though gradually at first.

It so happened also that Pagondas, seeing the distress of his left, had sent two squadrons of horse, where they could not be seen, round the hill, and their sudden appearance struck a panic into the victorious wing of the Athenians, who thought that it was another army coming against them.