Datames was a general and political leader (satrap) who was born in Asia Minor in the region of Caria. We do not know the exact date of his birth; we do know he was assassinated in 362 B.C. He had a high reputation in antiquity for his generalship and battlefield tactics. The short biography by the Latin historian Cornelius Nepos is one of the few intact sources we have about him. Nepos relates the following anecdote about a stratagem Datames used to destroy, in one stroke, those who had betrayed him and those who opposed him in war.
His special abilities aroused the envy of the courtiers who surrounded the Persian king Artaxerxes. He found himself surrounded by foes both internal and external; an army in the Anatolian region of Pisidia was outfitted to move against him. Datames had in his army a cavalry commander named Mithrobarzanes, who was also his father-in-law. This man believed that Datames’s position was hopeless, and so he resolved to betray his commander and desert to the Pisidians. This he did with a few of his units. When Datames discovered the desertion, he realized that if news of this even circulated to the rest of his men, it might cause a panic. They might believe that if one of Datames’s own relatives had left him, then the general’s position must be hopeless.
He therefore resolved on a stratagem to destroy the traitors and to defeat the Pisidians in one stroke. He assembled his men and told them that he had actually ordered Mithrobarzanes to “desert” to the enemy so that they might act as secret infiltrators of the Pisidians. He told his men that they should set out at once to follow Mithrobarzanes and position themselves against the Pisidians; the enemy would be faced, he said, with attack both from fake deserters within and from an army outside. Speed, he told his men, was essential: they must act now. So they set off to follow the traitor Mithrobarzanes.
When the deserters had reached the camps of the Pisidians, Datames gave the signal to attack. The Pisidians were dismayed to be confronted at the same time with men claiming to be deserters and with an enemy attack. They assumed that Mithrobarzanes and his deserters were fakes, a ruse used by Datames to trick them. So they attacked the deserters with ferocity; at the same time, Datames ordered his men also to attack both the deserters and the Pisidians. In the confusion and chaos that followed, Mithrobarzanes was forced to fight against both his former comrades and with the Pisidians at the same time. He and his men were slaughtered: no one showed them any mercy. Datames used the chaos to rout the Pisidians as well, gaining victory over both them and the traitors who deserted him. Cornelius Nepos says in his Liber de excellentibus ducibus exterarum gentium (Book of Great Generals of Foreign Nations):
By this ruse [Datames] crushed the traitors and defeated the enemy at the same time; and what had been planned for his downfall he converted into a means for victory. We have not read anywhere of a more brilliant ruse by any general, nor one that was accomplished so quickly. [XIV.6]
This was the stratagem of Datames used to turn apparent defeat into overwhelming victory.