Dedicated to the military history and civilization of the Eastern Roman Empire (330 to 1453)

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- - - - Princess Anna Comnena (1083–1153) - Byzantine historian

Thursday, March 8, 2018

Roman and Byzantine Marching Camps

Late Roman Reenactment 3rd - 5th century AD

Byzantine armies maintained the Roman practice of making fortified camps while marching. Laid out in a square, the camps would be made defensible, especially when an enemy force was in the area, with a ditch. The earth from the ditch was used to make a wall reinforced by a shield palisade. 

On the march, the square formation of the camp translated into a square infantry formation guarding the baggage train and guarded, in turn, by cavalry units. If a battle threatened, the infantry square became the focus of the army’s deployment, with the baggage sent to the rear and the cavalry now shielded inside the infantry.

Marching-camps were also of strategic defensive value. They were vital to the control of conquered land. Having been originally built on defensive ground, many were transformed from temporary entrenched sites into permanent fortified positions. As such, they became not only centers of territorial administration but also troop staging areas and strongpoints protecting vital lines of communications.

In the tactical realm, marching-camps were essential to the success of Roman military campaigns in a number of ways. As a medium of protection they granted the troops who sheltered in them a psychological reassurance. The late 4th-century Roman military commentator Vegetius wrote in Epitome of Military Science that a camp “gave the soldiers a place of safety … as if they were carrying a walled city with them.”

The outline of the camp was usually marked by a ditch, with the resulting spoil used to make a rampart thrown up on the camp’s inner edge. This was then reinforced with earthen sod and strengthened by palisades. The latter items were fashioned from local timber or stakes carried by the troops. Vegetius notes that the average camp ditch was five feet wide and three feet deep. 

Josephus, the historian of the Jewish War (ad 66-73), mentions that the soldiers who created the camps used saws, axes, sickles, chains, ropes, and baskets in their construction and that each worker carried one of each of these tools.

The camps were usually square or rectangular and had four gates with the commander’s tent placed in the center. The camp streets were arranged in definite lines, and coded symbols showed directions to each avenue, storage area, stable, cooking house, etc., on the site. Assembly points for the different legionary infantry cohorts, cavalry tumas, and auxiliary troops were also marked. 

When a camp was being constructed out of reach of an enemy, the entire force, except for a small picket, would participate in the building process. When the enemy was near at hand, the precaution was that half the infantry and all the cavalry would be drawn up in battle order to guard the workers building the camp. The first legion on the scene would take up defensive positions and the actual work on the camp would not begin until the arrival of the next legion in the line of march.

Late Roman Cavalry
Some 6,000 cavalry and 10,000 infantry would have been sheltered inside a massive fortified camp in the invasion of North Africa.

"Camping" in North Africa

The historian Procopius tells of the creation of the Roman fortified camp during the invasion of North Africa in 533 AD by General Belisarius.

The size of the Roman camp would have been massive. 

The invasion force had 10,000 infantry, another 5,000 cavalry and two additional bodies of Allied Troops: 600 Huns and 400 Heruls, all mounted horse archers. In addition thousands of sailors were brought ashore to assist the combat troops with construction and unloading supplies and extra horses and pack animals for this huge force. 

What you have here is a small city. Feeding, watering and protecting this city was a major military and engineering project.

  • "When Belisarius had said this, the whole assembly agreed and adopted his proposal, and separating from one another, they made the disembarkation as quickly as possible, about three months later than their departure from Byzantium. And indicating a certain spot on the shore the general bade both soldiers and sailors dig the trench and place the stockade about it. And they did as directed. And since a great throng was working and fear was stimulating their enthusiasm and the general was urging them on, not only was the trench dug on the same day, but the stockade was also completed and the pointed stakes were fixed in place all around. Then, indeed, while they were digging the trench, something happened which was altogether amazing. A great abundance of water sprang forth from the earth, a thing which had not happened before in Byzacium, and besides this the place where they were was altogether waterless. Now this water sufficed for all uses of both men and animals. And in congratulating the general, Procopius said that he rejoiced at the abundance of water, not so much because of its usefulness, as because it seemed to him a symbol of an easy victory, and that Heaven was foretelling a victory to them. This, at any rate, actually came to pass. So for that night all the soldiers bivouacked in the camp, setting guards and doing everything else as was customary, except, indeed, that Belisarius commanded five bowmen to remain in each ship for the purpose of a guard, and that the ships-of-war should anchor in a circle about them, taking care that no one should come against them to do them harm."

The "as was customary" remark by Procopius tells what we need to know about the standards of the Roman army on campaign.

  • After a march in the direction of Carthage Procopius said we "were going on to Decimum. And Belisarius, seeing a place well adapted for a camp, thirty-five stades distant from Decimum, surrounded it with a stockade which was very well made, and placing all the infantry there . . . Belisarius left his wife and the barricaded camp to the infantry, and himself set forth with all the horsemen. For it did not seem to him advantageous for the present to risk an engagement with the whole army . . . "

In the account above by Procopius a wooden stockade was used to secure their fortified camp in North Africa. Naturally the available local materials helped dictate the type of fortification to be built.
These photos are of Fort Ligonier in the French and Indian Wars of the 18th century.

Sharpened wooden stakes would break the charge
of any enemy infantry or cavalry.

The Grand Strategy of the Byzantine Empire
Here is a marching camp segment from the book

The Roman castrum was certainly one of the secrets of Roman military success—a secret not lost in Byzantium: the tenth-century work known as De Re Militari, newly edited as “Campaign Organization and Tactics,” begins with the detailed layout of a marching camp.

By constructing an entrenched and palisaded camp for themselves, if necessary each and every night when marching through insecure territories, the Romans and the Byzantines after them not only guarded against dangerous night assaults, but also ensured a calm sleep undisturbed by harassment raids or infiltrators.

When thousands of soldiers and horses are crowded inside a fortified perimeter, which must be as short as possible to be well guarded, a tightly defined layout of the tents, baggage, and horses, unit by unit, with clear passages between them, leading to broad “streets,” is the only alternative to chaos, congestion, and confusion in the event of a enemy attack, or simply an urgent exit from the camp. Moreover, it is the only way to keep latrines well separated and downhill from streams or wells.

Click to enlarge
Ideal reconstruction of a Roman marching camp in Austria. Ground-penetrating radar and aerial photography have helped scientists from the Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology and the Central Institute for Meteorology and Geodynamics discover what is thought to be the earliest Roman military encampment at the Archaeological Park Carnuntum, located on the Danube River in lower Austria. The Austrian Times reports that while investigating the area outside the western gate of the Roman town, the team found the encampment, which was fortified with a ditch, beneath the traces of a large village along the Roman road to Vindobona (Vienna). 

In the fundamental Byzantine military manual known as the Strategikon of (emperor) Maurikios, night attacks on their camps are suggested (Book XI, 1, 31) when fighting the Sasanian Persians; otherwise highly competent, the Sasanians were lacking in their camps. Although they too entrenched and guarded a perimeter, they did not enforce a disciplined internal layout unit by unit—the troops camped where it suited them.

The camp described in De Munitionibus Castrorum is very large indeed—too large, most would have been far smaller—for it assigns places for three complete legions, four cavalry alae miliariae of 1,000 men each with more than 1,000 horses, five alae quingenariae of 500 men each, and thirty-three more legionary detachments and auxiliary units, with a broad panoply of unit types represented, including 1,300 marines or assault-boatmen (500 classici misenates and 800 classici ravvenates), 200 scouts (exploratores), 600 Moorish and 800 Pannonian light cavalry, and many more, for an impossible total of more than 40,000 troops and 10,000 horses.

Evidently this was a design exercise, and there are specific places for each unit in the layout: the cohorts of legionary heavy infantry are tented in the outer perimeter, which they would be the first to defend, and the usual twin headquarters the Quaestorium and the Praetorium are in a spacious central segment. In its small compass, the work is highly instructive, and it may well have sustained the marching-camp concept that we know was studied and practiced for at least another seven hundred years.

For the Byzantines, Roman military literature, whether in Latin or Greek, could not be classical—only the texts of ancient Greece could aspire to that status, starting with the impeccably antique fourth-century BCE Aeneas, usually known as Tacticus, on the defense of fortified positions. The surviving text is only part of a longer work cited and quoted by Polybius in Book X, 44, with faint praise for the method of signaling suggested by Aeneas.

The Remains of a marching camp in England.

(Fortified camp)      (Marching camps)      (Military camp)      (Grand strategy)

(Fortified camps)      (Romanmilitary.net)