Plutarch Antony 42

[1] Having thus learned what he ought to do, Antony covered not only his rear, but also both his flanks, with numerous javelineers and slingers, led his army in the form of a hollow square, and gave orders to his horsemen to rout the enemy when they attacked, but after routing them not to pursue them further. Consequently the Parthians, during four successive days, suffered greater loss than they inflicted, became less eager, and made the winter an excuse for thoughts of going away.

[2]
  On the fifth day, however, Flavius Gallus, an efficient and able soldier in high command, came to Antony and asked him for more light-armed troops from the rear, and for some of the horsemen from the van, confident that he would achieve a great success. Antony gave him the troops, and when the enemy attacked, Gallus beat them back, not withdrawing and leading them on towards the legionaries, as before, but resisting and engaging them more hazardously.

[3] The leaders of the rear guard, seeing that he was being cut off from them, sent and called him back; but he would not listen to them. Then, they say, Titius the quaestor laid hold of his standards and tried to turn them back, abusing Gallus for throwing away the lives of so many brave men. But Gallus gave back the abuse and exhorted his men to stand firm, whereupon Titius withdrew. Then Gallus forced his way among the enemy in front of him, without noticing that great numbers of them were enveloping him in the rear.

[4] But when missiles began to fall upon him from all sides, he sent and asked for help. Then the leaders of the legionaries, among whom was Canidius, a man of the greatest influence with Antony, are thought to have made no slight mistake. For when they ought to have wheeled their entire line against the enemy, they sent only a few men at a time to help Gallus, and again, when one detachment had been overcome, sent out others, and so, before they were aware of it, they came near plunging the whole army into defeat and flight. But Antony himself speedily came with his legionaries from the van to confront the fugitives, and the third legion speedily pushed its way through them against the enemy and checked his further pursuit.