Anabasis

When the generals heard these statements, they resolved to bring the troops together into a camp; then, after leaving a garrison and Sophaenetus the Stymphalian as general in command of those who stayed behind, they set out at once, with the captured man as guide.

As soon as they had begun to cross the mountains, the peltasts, pushing on ahead and descrying the enemy’s camp, did not wait for the hoplites, but raised a shout and charged upon the camp.