Where the heavy-laden Roman foot-soldier dragged himself toilsomely through the sand or the steppe, and perished from hunger or still more from thirst amid the pathless route marked only by water-springs that were far apart and difficult to find, the Parthian horseman, accustomed from childhood to sit on his fleet steed or camel, nay almost to spend his life in the saddle, easily traversed the desert whose hardships he had long learned how to lighten or in case of need to endure. There no rain fell to mitigate the intolerable heat, and to slacken the bowstrings and leathern thongs of the enemy's archers and slingers; there amidst the deep sand at many places ordinary ditches and ramparts could hardly be formed for the camp. Imagination can scarcely conceive a situation in which all the military advantages were more on the one side, and all the disadvantages more thoroughly on the other.
To the question, under what circumstances this new style of tactics, the first national system that on its own proper ground showed itself superior to the Roman, arose among the Parthians, we unfortunately can only reply by conjectures. The lancers and mounted archers were of great antiquity in the east, and already formed the flower of the armies of Cyrus and Darius; but hitherto these arms had been employed only as secondary, and essentially to cover the thoroughly useless Oriental infantry. The Parthian armies also by no means differed in this respect from the other Oriental ones; armies are mentioned, five-sixths of which consisted of infantry.
In the campaign of Crassus, on the other hand, the cavalry for the first time came forward independently, and this arm obtained quite a new application and quite a different value.
The irresistible superiority of the Roman infantry in close combat seems to have led the adversaries of Rome in very different parts of the world independently of each other - at the same time and with similar success - to meet it with cavalry and distant weapons. What as completely successful with Cassivellaunus in Britain[6] and partially successful with Vercingetorix in Gaul[7] - what was to a certain degree attempted even by Mithradates Eupator[8] - the vizier of Orodes carried out only on a larger scale and more completely. And in doing so he had special advantages: for he found in the heavy cavalry the means of forming a line; the bow which was national in the east and was handled with masterly skill in the Persian provinces gave him an effective weapon for distant combat; and lastly the peculiarities of the country and the people enabled him freely to realize his brilliant idea. Here, where the Roman weapons of close combat and the Roman system of concentration yielded for the first time before the weapons of more distant warfare and the system of deploying, was initiated that military revolution which only reached its completion with the introduction of firearms.
Under such circumstances the first battle between the Romans and Parthians was fought amidst the sandy desert thirty miles to the south of Carrhae (Harran) where there was a Roman garrison, and at a somewhat less distance to the north of Ichnae. The Roman archers were sent forward, but retired immediately before the enormous numerical superiority and the far greater elasticity and range of the Parthian bows. The legions, which, in spite of the advice of the more sagacious officers that they should be deployed as much as possible against the enemy, had been drawn up in a dense square of twelve cohorts on each side, were soon outflanked and overwhelmed with the formidable arrows, which under such circumstances hit their man even without special aim, and against which the soldiers had no means of retaliation. The hope that the enemy might expend his missiles vanished with a glance at the endless range of camels laden with arrows. The Parthians were still extending their line.
That the outflanking might not end in surrounding, Publius Crassus advanced to the attack with a select corps of cavalry, archers, and infantry of the line. The enemy in fact abandoned the attempt to close the circle, and retreated, hotly pursued by the impetuous leader of the Romans. But, when the corps of Publius had totally lost sight of the main army, the heavy cavalry made a stand against it, and the Parthian host hastening up from all sides closed in like a net round it. Publius, who saw his troops falling thickly and vainly around him under the arrows of the mounted archers, threw himself in desperation with his Celtic cavalry unprotected by any coats of mail on the iron-clad lancers of the enemy; but the death-despising valour of his Celts, who seized the lances with their hands or sprang from their horses to stab the enemy, performed its marvels in vain. The remains of the corps, including their leader wounded in the sword-arm, were driven to a slight eminence, where they only served for an easier mark to the enemy's archers. Mesopotamian Greeks, who were accurately acquainted with the country, adjured Crassus to ride off with them and make an attempt to escape; but he refused to separate his fate from that of the brave men whom his too-daring courage had led to death, and he caused himself to be stabbed by the hand of his shield-bearer. Following his example, most of the still surviving officers put themselves to death. Of the whole division, about 6000 strong, not more than 500 were taken prisoners; no one was able to escape. Meanwhile the attack on the main army had slackened, and the Romans were but too glad to rest.
When at length the absence of any tidings from the corps sent out startled them out of the deceitful calm, and they drew near to the scene of the battle for the purpose of learning its fate, the head of the son was displayed on a pole before his father's eyes; and the terrible onslaught began once more against the main army with the same fury and the same hopeless uniformity. They could neither break the ranks of the lancers nor reach the archers; night alone put an end to the slaughter. Had the Parthians bivouacked on the battle-field, hardly a man of the Roman army would have escaped. But not trained to fight otherwise than on horseback, and therefore afraid of a surprise, they were wont never to encamp close to the enemy; jeeringly they shouted to the Romans that they would give the general a night to bewail his son, and galloped off to return next morning and despatch the game that lay bleeding on the ground.
6. V. VII. Cassivellaunus.