Plutarch Demetrius 47

[1] But at last sickness assailed them as well as famine, which is wont to happen when men have recourse to foods which they must eat to save their lives, and after losing no less than eight thousand men in all, Demetrius retraced his steps with the rest and came down to Tarsus. Here he would gladly have spared the country, which was then under Seleucus, and so have given its ruler no ground of complaint;

[2] but this was impossible, for his soldiers were suffering extreme privations, and Agathocles had fortified the passes of the Taurus against him. He therefore wrote a very long letter to Seleucus, bewailing his own misfortunes, and then begging and beseeching him to take pity on a man who was allied to him by marriage, and had suffered enough to win sympathy even from his enemies.
  Seleucus was somewhat softened by this appeal, and wrote to his generals in that province that they should furnish Demetrius himself with royal maintenance, and his troops with abundant supplies.

[3] But Patrocles, a man in repute for wisdom, and a trusted friend of Seleucus, came to him and told him that the expense of maintaining the soldiers of Demetrius was a very small matter, but that it was unwise for him to allow Demetrius to remain in the country, since he had always been the most violent of the kings, and the most given to grand designs, and was now in a state of fortune where even naturally moderate men are led to commit deeds of daring and injustice.

[4] Incited by this advice, Seleucus marched into Cilicia with a large force. Then Demetrius, filled with amazement and alarm at the sudden change of attitude in Seleucus, withdrew to the strongest fastnesses of the Taurus, and sending messengers to Seleucus, asked that above all things he might be permitted to acquire a petty empire among the independent Barbarians, in which he might end his days without further wanderings and flights; but if this might not be, he begged him to give his troops food for the winter there, and not to drive him forth, stripped and destitute of all things, and cast him into the hands of his enemies.