Cornelius Nepos,
Lives of the Eminent Commanders…
“ For Aspis, who dwelt in a wooded region, fortified with strongholds, not only ignored the king's commands, but even raided the bordering regions and stole what was being taken to the king. Although Datames was far from these regions and was being pulled away from a greater task by the king, he thought that the will of the king must be done voluntarily. So, he boarded a ship with a few men, but brave ones, thinking (correctly, as it turned out) that he would more easily crush a surprised enemy with a small force than a prepared enemy however large his army might be. ”
