History of the Peloponnesian War

And the next morning before day, he invaded the Ambraciotes whilst they were yet in their lodgings and knew not what was the matter, but thought rather that they had been some of their own company.

For Demosthenes had placed the Messenians on purpose in the foremost ranks, and commanded them to speak unto them as they went in the Doric dialect and to make the sentinels secure, especially seeing their faces could not be discerned, for it was yet night.

Wherefore they put the army of the Ambraciotes to flight at the first onset and slew many upon the place;

the rest fled as fast as they could towards the mountains. But the ways being beset and the Amphilochians being well acquainted with their own territory and armed but lightly against men in armour unacquainted and utterly ignorant which way to take, they lit into hollow ways and to the places forelaid with ambushes and perished.