§ 1. It has often seemed unworthy to our commanders to cherish a camp and place their trust in a rampart.
Thus at times they station even the greatest armies in an open field without any fortification. The Romans did not do so. Concerning them Polybius says that everything was ordered and fortified after the fashion of towns. These are the words of Polybius: “When these things have been established in this way, the whole shape of the camp becomes an equilateral square. Its parts, both in the division of the rows of tents and in their other arrangement, have an ordering like that of a city. They separate the rampart itself from the tents by two hundred feet on every side. This empty space supplies them with many notable advantages. It is suitable both for the departure and for the entrance of the troops—for individual bodies go out into this empty space beside their own rows of tents, and do not run together in confusion and trample one another. They also drive or carry into this place the livestock brought in and the booty captured from enemy territory, and guard them there during the nights. Its chief advantage, however, is that during assaults at night neither fire nor missile reaches them, except for a few; and even these are made almost harmless, both by the extent of the interval and by the tents placed around it.
“The two sides of the ditch and rampart which lie beside the two wings of the allies fall to the allies to construct; the other two fall to the Romans, one to each legion. Each side is divided among the maniples; the centurions have the care of the individual parts, and the men assist them. Two of the tribunes have the inspection of the whole work.”
You see everything fortified here. The soldiers are two hundred feet distant from the rampart, and the rampart and ditch themselves occupy enough space for them to be altogether safe.
§ 2. The allies constructed two sides and the legions two. The centurions measured them with ten-foot rods. The tribunes go around and do not depart until the entire work has been completed. The work of the rampart was of this kind: they first drew a ditch along the outside. Tibullus:
Where it is fitting to draw before the camp a protecting ditch.
They dug it down so that it was eight feet wide and equally deep, so that, if an enemy leaped into it, his whole body would be below the earth. Its width was such that no one could leap across it. When a greater force was feared, it was made wider and deeper. Vegetius, book 3, chapter 8, says that at times it was nineteen feet, although the depth was not then equal to the width.
On the inner side of the ditch was added a rampart made from stakes and turf, or heaped earth, three or four feet high. The measure of each turf was half a foot in height, one foot in width, and one and a half feet in length.
But in danger, and I believe in winter camps, the mound was much higher. This followed naturally if the ditch was greater, for the mound grew from the earth taken from it. Book 3 of The Civil War: “In that place there was a ditch fifteen feet wide, and a rampart facing the enemy ten feet high; the mound of that rampart likewise extended ten feet in breadth.” The palisade stake was branched and sharpened, so that it could not easily be torn up or crossed. Thus camps were placed behind stakes fixed in the manner of very sharp sword-points.
It would be most useful to resume even today this method of fortifying camps, or to retain another equal to it. For the soldier rests safely and is not disturbed at a noise, being secure in the fortification of the place; this contributes very greatly to strength and health. Further, since a camp can be defended easily, it will be possible, even when the enemy is nearby, to send a force elsewhere as opportunity requires. Claudius Nero does this in Livy: leaving a garrison in the camp, he goes on a long march to meet Hasdrubal, defeats him, and returns to camp. He could not have done this unless the camp had been fortified. Third, far fewer soldiers are worn down by sentry duty.
§ 3. There was one gate in each side. The praetorian gate, which stood beyond the praetorium and faced the enemy, was the gate through which the army was led out into battle. Next were the two principal gates, because they corresponded to the principia. Finally, there was the decuman gate, because the tenth cohorts pitched their tents there.
Not content with this fortification, they at times also added towers. The History of the Gallic War, book 8: “He placed doors and higher towers upon the gates.” Josephus, book 3 of The Jewish War, says that towers were positioned around the circuit; and at Numantia Scipio placed them at intervals of one hundred feet in every iugerum. Finally, there was often a double rampart and a double ditch.
§ 4. Those works were not difficult because of the multitude of those who performed the fortification. One side of the camp was 2,050 feet long. If an entire legion were assigned to fortify it, there would be two soldiers for one foot, if the exempt men were few. For centurions, cavalrymen, evocati, discharged soldiers, and volunteers had exemption from duties.
But there is no doubt that sutlers, servants of the camp, and slaves came to take part in these works and gave assistance. For why would masters, wearied by labor, have permitted their slaves to be idle? Florus, book 2, chapter 18, calls them servile works. Caesar in The Alexandrian War says: “Since he had believed that the great multitude of slaves which carried earth for the mound, in the manner of daily work, were soldiers.” Trebonius also, in book 2 of The Civil War, summons men from the province for these works. The ditch was therefore drawn very quickly.
§ 5. But who acted more correctly: Lycurgus, who favored circular camps, or others, who favored square or quadrangular ones? Xenophon, in The State of the Lacedaemonians, says that Lycurgus approved the circular form: “I shall also say in what manner Lycurgus thought a camp should be marked out. Since he considered the angles of a square camp useless, they placed their camps in a circle, unless they were protected either by a mountain, a wall, or a river behind them.” He gives as the reason that the angles were useless.
Yet it is more advantageous for camps to be square or quadrangular for the purpose of defense, since from one angle two sides can be seen and defended. Moreover, a square form is more convenient for every method of building than a round or oblong one. Nevertheless, if the matter is considered as a whole, nothing is better than to weigh the nature of the site. If there is a river, lake, mountain, valley, wall, marsh, forest, or something else that presents a natural fortification, they should employ it to reduce their labor. Beside rivers it is expedient for a camp to be extended lengthwise because of the convenience of obtaining water.
§ 6. Fortification ceased in the Roman military service for various reasons. The first was the indulgence of the emperors, when by their favor they made many men exempt. From this it followed that those who remained subject to duties were more heavily burdened—indeed, crushed.
The second cause was that, as a kind of military service was distributed through towns, the soldiers became unacquainted with the labors of a camp. Tacitus, Annals 13: “It was sufficiently established that in that army there were veterans who had never entered upon guard duty or watches, and who gazed at a rampart and ditch as though they were new and marvelous things. Gleaming and enriched, whether in helmets or breastplates, they had completed their military service throughout towns.” From both causes the praetorians arrived at the utmost degree of idleness. For when Didius Julianus wished to lead them into the field and exercise them, they hired substitutes for the works at a price. More shameless still were the Egyptians, who, when ordered to fortify the camp with a ditch and rampart, cried out that the work should be contracted at public expense.
The third cause was the avarice and savagery of the centurions, who compelled men to purchase release from duties. Tacitus, Histories 1: “It was demanded that the payments customarily made to centurions for exemptions be abolished. For the common soldier paid, as it were, an annual tribute. Some wandered through the maniples, some on furloughs, and some within the camp itself, until they paid the price to the centurion. No one had regard for the amount of the burden or the kind of profit: by brigandage and plunder or by servile tasks they purchased release from military duty. Then each soldier who was richer than the rest was wearied by labor and cruelty until he purchased exemption. When, exhausted by expenses and made wretchedly feeble by idleness, he returned to the maniple poor in place of rich and idle in place of vigorous, another after another, corrupted by the same poverty and license, rushed toward sedition and discord and finally civil wars.”
Afterward the centurions were paid from the public treasury, until at last they ceased to fortify camps. In the time of Vegetius, who lived under Valentinian the Younger, that knowledge had already died out. “The knowledge of this matter,” he says, “has utterly perished; for no one for a long time has established a camp by drawing ditches and fixing stakes.” Nevertheless, it was revived by many at intervals.
§ 7. Vegetius, book 1, chapter 21 and the following chapters, teaches the fortification of camps: “The recruit,” he says, “must also learn the fortification of camps, for nothing is found in war either so salutary or so necessary. If the camp has been correctly established, the soldiers spend days and nights within the rampart in such security—even if the enemy besieges them—that they seem to carry a walled city with them everywhere. But the knowledge of this matter has utterly perished. For no one for a long time has established a camp by drawing ditches and fixing stakes before it. Thus we know that many men have frequently been afflicted by an unexpected arrival of barbarian cavalry by day or night. Not only do those who settle down without a camp suffer these things; but when, through some mischance, they begin to give ground in battle, they have no fortifications of a camp to receive them and fall unavenged like animals. There is no end to their dying until the enemy loses the will to pursue them.”
They fortified the camp even amid the greatest dangers. Vegetius, book 1, chapter 25: “It is easy to fortify a camp when the adversaries are absent. But if the enemy presses upon them, then all the cavalry and half of the infantry are drawn up in battle-line to repel the attack; the rest behind them draw ditches and fortify the camp. It is proclaimed by a herald which century is first, which second, and which third, until the whole work has been completed. After this the ditch is inspected and measured by the centurions, and punishment is inflicted upon those who have worked too negligently. The recruit must therefore be trained for this use, so that, when necessity demands it, he may be able to fortify the camp without confusion, swiftly, and cautiously.”
In the African War one part of the battle-line stood in the field while another performed the work. In the Spanish War against Afranius, the third battle-line deceived the enemy by performing the work secretly.
§ 8. Mendoza, part 1, chapter 52, relates another and rapid method of fortifying a camp. He bound small beams together at their joints and, in a very short time, erected a square platform thirty geometrical feet high and sixty wide. Four such structures suffice not only for defense but also for harassing the whole field, if they are placed in suitable positions; for they can be filled with musketeers and other soldiers. He requires no timbers larger than can be gathered and carried by horses or mules. A watchtower fifty feet high can nevertheless be placed above them. This can be done quickly. Other defenses must nevertheless be added, for those structures can easily be cast down by artillery.
§ 9. Of the works formerly used for fortifying camps and enclosing enemies, some were, as it were, barbaric and possessed little usefulness; others contributed to necessary protection. The work which Caesar made in book 1 of The Gallic War was altogether useful. “With the one legion which he had with him and the soldiers who had assembled from the province, he drew a wall sixteen feet high and a ditch for nineteen miles, from Lake Geneva to Mount Jura. When this work had been completed, he stationed garrisons and fortified strongholds, so that, if they attempted to cross against his will, he might more readily prevent them.” By this he terrified the Helvetians so that they abandoned their plan and hope of breaking out. The extent was five of our miles, which Caesar occupied after fortifying it with strongholds. But if the Helvetians had not been frightened by that undertaking, it would not have been difficult to break the wall at some point and fill up the ditch.
The same Caesar, when he was besieging Alesia with no great number of soldiers, captured the city by fortifications in the face of the many thousands of men who were in the city and the two hundred and forty thousand infantry and eight thousand cavalry. First he made a circumvallation extending for eleven miles and a ditch twenty feet wide. Withdrawing four hundred feet from it, he made other fortifications. These were two ditches fifteen feet wide and of the same depth; he filled the inner one with water diverted from the river. Behind these he constructed a mound and rampart twelve feet high; to this he added a breastwork and battlements, with great forked branches projecting, which would delay the enemy’s ascent. He also surrounded the entire work with towers standing eighty feet apart. Against those who came to aid the besieged he constructed other, similar fortifications, embracing fourteen miles.
It was barbaric and done for display when he attempted to enclose Pompey with a wall that extended for twelve hundred stadia—an extent of about one hundred and fifty miles, or thirty-seven of our miles. For he did not hamper Pompey the Great by such extensive contrivances; and how easily Pompey could have broken through them with an armed force!
Lucan describes it in this manner:
Mountains are broken, and Caesar leads a level work through steep places; he opens ditches and stations towered forts upon the highest ridges. Enclosing boundaries in a great circuit, glades and wooded wastes and forests, in a vast ring he pens the wild beasts. Fields are not lacking, nor forage lacking to Pompey the Great; surrounded by Caesar’s mound, he moves his camp. So many rivers arising there weary their courses; Caesar, exhausted, remains amid the fields. Let ancient legend now raise up the walls of Ilium; let the Parthians who fled marvel at Babylon’s fortifications. Behold how much territory the Tigris, how much the swift Orontes, shall love; how much of the eastern land suffices for Assyrian peoples as a kingdom: a work suddenly seized in the tumult of war enclosed it. How many labors have perished!
Crassus constructed against Spartacus a ditch three hundred stadia long, fifteen feet wide and fifteen feet deep, and above the ditch he constructed a rampart of admirable height and strength, according to Plutarch in Crassus. These matters pertain to fortifications. They are now made in another manner because of artillery, but are neglected in camps.
§ 10. In the camps themselves were tents which seem to have been strong, because, as Polybius says, they even kept off missiles. In winter quarters and permanent camps they were perhaps made from boards, posts, and woven fencing; otherwise, they were of hide and stretched with ropes, and in this manner could delay missiles whose force was spent. Isidore adds boards and curtains. Curtains of linen easily resisted feeble missiles, and indeed missiles hurled strongly, especially when the curtains hung loosely. They certainly covered their upper parts with hides.
Tacitus, concerning the Frisians: “Drusus had ordered them, because of the narrowness of their resources, to pay a moderate tribute, namely, that they should furnish ox hides for the use of the camp.” Caesar’s soldiers in the African War made tents, some from clothing, reeds, and mats. Belisarius has tents made from boards in Procopius, book 2 of The Persian War. Herodes, in Trebellius, had embossed tents and gilded pavilions.
Their size was such that they easily held everyone, and indeed could also receive some multitude of visitors. If there were several legions, the camp was larger. If there were two consuls, each held his own praetorium and arrangement within a doubled space, as Polybius relates. In the battle at Cannae we read of a larger and a smaller camp, separated by a proper interval, undoubtedly for a proper reason, although it has not been explained.
I therefore conclude: individual soldiers are covered by breastplate, helmet, and shield; all together are covered by the rampart and encircling defenses of the camp. Camps which are unfortified are unarmed, and are then compelled to fight at the enemy’s discretion.