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Шиманович А.А.

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Castrum (Latin: Castrum, plural: castra, diminutive: castellum) — a type of military camp common in ancient times, built by Roman legionaries. Castrum was the name given to both the marching camps built at the end of each day's march, and the long-term fortified fortresses that stood on the borders of the Empire. It was thanks to these powerful camps that the Roman Empire was able to spread and maintain its influence even in the most remote regions from the capital. On the site of castrums, entire cities sometimes grew up, many of which have survived to this day. In this article, we will take a closer look at the history and structure of such an important element in the life of both the Roman legions and the Roman Empire as a whole.

Sketch of a fortified castrum

Historical background

A universal method of dividing the territory into camps, most likely, appeared during the Punic Wars (III century BC). Then along the borders and state (consular or praetor) roads, military camps were built at a distance of a day's march, similar in structure to the city.

According to the Jewish historian and military commander Josephus (37-100 AD), in the first century AD, legionaries set up a camp at the end of each day's march, which made it possible to calculate the duration of the campaign in days based on the number of camps built. Prior to 69 AD, permanent border castrums, like marching camps, were built of turf and wood. Only in 69 AD, when the Flavians came to power, did the construction of long-term fortresses made of brick or stone begin.

By the fourth and fifth centuries A.D., castrums seem to have lost their significance, mostly due to a significant decline in the combat effectiveness of the army, and the oblivion of old military traditions. Soviet historian V. D. Ivanov wrote on this topic: "the infantry of old Rome did not go to bed until a ditch was dug around the camp, until the earthen embankment was ruffled with slingshots made of sharp stakes, until the fortress camp was closed by three gates. Then, having got used to playing emperors, the soldier's freemen freed themselves from the drudgery of everyday work... and in campaigns, soldiers could only be forced to dig in in the face of obvious danger..."

Setting up a camp

The construction of a camping camp had an established order. Usually, at the end of a day's march, a small group would be sent ahead of the Legion to select the most suitable and protected location. There were strict requirements for the location of the camp: it should be well protected on all sides, convenient for defense, and also, preferably, have a water source. After choosing a location, the first step was to mark the location of the commander's tent, and the "pretoria" surrounding this tent (Lat. praetorium) - a square or rectangular area on which the tents of all senior officers were located, and from this point the direction of the two main roads (cardo and decumanus) was indicated, which crossed the camp with a cross,and accordingly, all other parts of the camp were designated.

When the legion approached the designated area, the soldiers immediately began to erect fortifications. Work was often carried out in full uniform, in armor and with weapons. First of all, fortifications were built: a ditch was torn out along the entire perimeter of the camp and a solid rampart was poured in, reinforced with turf or stones, and if you stopped for a long time — with wattles. The shaft was necessarily reinforced with sharpened stakes. It is worth noting that in general, the entire system of Roman fortifications was built according to the fossa – agger – vallum pattern (moat – embankment – shaft), despite the fact that there could be several moats.

Reconstruction of the defensive structures of Kastrum

After the construction of the fortifications, the legionnaires began to erect tents. First, the tents of the commander and senior officers were set up: they were installed around the perimeter of the praetorium. Last of all, the tents of the soldiers were put up. A prerequisite was to maintain a certain distance of the tents from the perimeter fortifications for the convenience of moving detachments inside the camp, as well as to avoid hitting the tents with enemy arrows that could reach from behind the fortifications. As a rule, depending on the terrain and tactical situation, the work on setting up a camp could take from 2 to 5 hours, after which the legionnaires settled down for the night.

An average description of a marching castrum is given by the ancient Greek historian Polybius (200-120 BC). He claims that the Roman military camp was built in the form of an "equilateral quadrilateral", or square, and the streets laid out in it somehow likened it to a city: "Tents are two hundred feet away from the rampart on all sides. All available space provides great and varied amenities. Thus, it is very convenient for entering and leaving the camp, because the separate units, each with its own street, go out to this free space, and therefore the soldiers do not collide on the same road, do not overturn or trample each other."It is worth noting that most of the castrum remains found indicate that the shape of a rectangle rather than an equilateral square prevailed in the construction of camps. There was also a theoretical guideline on the aspect ratio of the camp, according to which the ratio of its length and width should be 3/2. It was written in the treatise " On the organization of military camps "(Latin: De munitionidus castrorum) under the authorship of a certain Pseudo-Gigin (a pseudonym attributed to several ancient authors at the same time, who exactly was hiding under it has not yet been precisely established).

Big castrum scheme
Drawing a castrum

Different sources give different sizes of castrum. The average typical size of the camp was approximately 450-500 meters wide and 550-650 meters long. There were gates on each of the four sides of the camp, connected by two main roads. As a rule, if the camp was set up in close proximity to the enemy, one gate was necessarily turned in his direction (such gates were called porta praetoria), and behind the opposite gate (porta decumana) sometimes merchants following the legion could be located. The gate was always designed to be wide enough so that there were no obstacles when moving out of the camp. The center of the camp was the praetorium, which, as already mentioned, was the location of the general's tent and the tents of senior officers. Often there was also a sacrificial altar. In addition, the praetorium was a place for divination, the tent of the Quaestor — treasurer, as well as the tribunal-a mound from which the general could address the legionaries. Auxiliary troops were stationed behind the praetorium, while the rest, most of the camp, was occupied by tents of legionaries and cavalry on both sides of the main street "via praetoria".

Camp removal

The removal of the camp was also carried out in a special order. At the first signal of the trumpet, the tents were removed, and at the second, the tents and all the other baggage were loaded on the animals. Josephus writes: "At the same time, they burn the trenches so that the enemy will not use them, in the belief that if necessary, they will be able to build a new camp on this site without much difficulty. The third trumpet signal announces the march — the ranks are lined up and every soldier who hesitates hurries to take his place in the ranks. Then the messenger, standing at the right hand of the commander, asks three times in his native language: is everything ready for battle? The soldiers cry out loudly and joyfully as many times: "Yes, it's done!" and often, when they warn the end of a question, they are full of warlike enthusiasm, with their hands outstretched in the air, they utter only one war cry." "Then they set out and move in silence, in orderly order. Everyone stays in line, just like in a battle."

Legionnaires of the Tenth Legion emerge from Castrum
Fragment of a Roman military camp, reconstruction

Kastrums - cities

Long-term castrums were built in the most important strongholds. They were reinforced with wooden, and later stone walls, and instead of tents they had stone barracks and buildings of the military administrative apparatus and public institutions. Their planning scheme remained almost the same as that of the temporary camps. The area inside the walls was called the city "urbs", and the strip of land outside the walls was called "pomerium". Legionnaires and their families usually settled here. Such a castrum included a principium (headquarters), a praetorium, barracks, food warehouses, training rooms, workshops, barracks of soldiers of the first cohort, stables and a hospital.

Over time, these camps, connected by roads to the metropolis, became centers of attraction for trade and crafts. They were overgrown with residential buildings: houses of family warriors, artisans and merchants. Such settlements were established by Roman generals at the end of the republic and by emperors who disbanded their armies at the end of wars. As a reward for their service, soldiers (veterans and reservists) received money and land for acquiring and settling in compact masses. Usually, the population of such a town was made up of veterans of the same military unit. Cities that grew out of Roman castrums include Turin, Florence, Lucca, Timgad, London, Vienna, Bonn, Trier, Algiers, Budapest, Belgrade, and others.

Drawing of the internal structure of a long-term castrum

"Urbs Quadrata" or Square city

Wherever the Roman legionnaires carried the imperial will, they always carried Rome with them: Roman civilization, Roman laws, Roman culture. Therefore, every camp-fort, especially a long-term one, built even in the most remote province, somehow had a bit of distant Rome in it. This was facilitated, in particular, by the square shape of the camp.

Rome was often called "Urbs Quadrata" (Latin: Urbs Quadrata). square city), implying the principle of the foundation of sacred monuments that became the basis of an equally sacred city, which is not very clear for today's people. All the buildings that were being built were part of an order, or a Whole (as Marcus Aurelius called the world order). In simple terms, buildings built by man in accordance with a sacred ritual were at the level of those forms that were created by the divine principle. Thus, the circle represented the divine reality, and the square, in turn, represented the earthly one. Therefore, the holy city of Rome was identified with the beginning not only of the earth, but also of heaven.

The Castrums, which were the embodiment of the order that the Roman Empire brought to its provinces, also embodied both of these principles, announcing to the poorly educated conquered peoples the immeasurably great foundation on which Roman civilization was built.

Castrum in Weissenburg (Birciana)

One of the most famous castrums, the remains of which have survived to this day. Presumably, it was built in 90 AD to protect the newly acquired territories of the emperor Domitian north of the Danube. Originally built of wood, it was rebuilt in stone in the middle of the second century AD.

It is known that the First Spanish Aurian Ala (Ala I Hispanorum Auriana) (an auxiliary unit of the Roman army) was stationed in the Weissenburg Castrum during the first and third centuries AD. In addition, it is suggested that the IX auxiliary Batavoran Cohort (Cohors IX Batavorum) was temporarily based in this camp at the beginning of the second century AD.

Reconstruction of the main gate of the Weissenburg camp

The ruins of the Weissenburg Castrum are currently under the protection of the German government and are included in the UNESCO list as a cultural heritage site. The camp was first discovered by German archaeologists in 1890, the excavations were completed by 1905, and since then, restoration work has been gradually carried out in the thermal baths.

Today, the Castrum Museum, in addition to the remains of a large complex of thermal baths and the foundation of the principia building, has a reconstructed stone gate (porta decumana), completely recreated in 1990.

Heated dressing room with hypocast (heating system)
Square reservoir in the caldarium (main room of the thermal baths with hot water)
Cold water pool with original preserved floor

Castrum of the Tenth Legion at Masada

In 66 AD, during a revolt, the fortress of Masada was captured by the Zealots, Jewish rebels who advocated the eradication of Hellenistic and Latin cultures from the Jewish lands, and wanted to overthrow Roman rule. During the capture, according to Josephus, the Zealots completely massacred the Roman garrison in the fortress. In 67 AD, the Sicarii (the"fighting wing" of the Zealots, who used the path of direct attacks to fight the Romans) appeared in the fortress, which for the most part was responsible for the outbreak of the First Jewish War. After the capture of Jerusalem in 70 AD, the Roman army turned its attention to Masada, which turned out to be the last stronghold of recalcitrant radicals. The task of taking the fortress was to be performed by the Legio X Fretensis under the leadership of the Roman politician and general Lucius Flavius Silva. The defenders of the fortress were a little less than a thousand people, but due to their tenacity and the favorable natural location of the fortress, protected by steep cliffs, the siege lasted for three whole years. The Tenth Legion built a siege rampart at the foot of the fortress, a mound that allowed access to the very walls of the fortress, which has survived to this day and is used as a tourist route, and a castrum, the ruins of which, after almost two thousand years, still preserve the memory of the achievements of the legionaries of the Tenth.

Modern view of the Masada Fortress
Modern view of the ruins of Kastrum

The siege ended tragically: in 73 AD, following the call of the head of the Sicarii, Elazar ben-Yair, the besieged committed suicide en masse on the first day of the Jewish holiday of Passover. In describing these events, Josephus refers to the story of two women who, together with several children, took refuge in a cave, and told the Romans who entered the fortress how the men killed their wives and children, and then each other. "I know for a fact that the Romans will be upset if they see that they did not take us alive and were disappointed in their hopes of making a profit. Only our food supplies will be left untouched, so that after our death they will bear witness that we did not suffer from hunger or lack of water, but we ourselves chose death over slavery — as we had previously decided......So they all perished with the certainty that they had not left behind a single soul to be abused by the Romans. The next day the Romans went up to Masada, and when they found the dead heaps, they did not rejoice at the sight of the fallen enemies, but only stood in silence, struck by the greatness of their spirit and the unshakable contempt for death" - Josephus.


Josephus. "The Jewish War" / translated by Ya. L. Chertka in 1900, with an introduction and translator's note. Vekhi Library, 2004.

Livy Titus. Istoriya Rima ot osnovaniya goroda [History of Rome from the foundation of the city]. edited by M. L. Gasparov and G. S. Knabe, vol. I-III. Moscow, 2002

Polybius. Universal History, vol. I (books I-V), Moscow, 1890.

Polyakov Evgeny Nikolaevich, Mayorova E. V., Shapovalova E. E. Features of a regular planning grid in the military architecture of ancient Rome // Bulletin of TSASU. 2009.

Maklyuk A.V. Army of the Roman Empire. Ocherki traditsii i mentalnosti [Essays on Traditions and Mentality], N. Novgorod, 2000

Dion Cassius. Dio’s Roman History: In Nine Volumes / With an English Translation by E. Cary, on the Basis of the Version of H. B. Foster. London; New York, 1914-1927


A mound built by legionnaires to approach the walls of the Masada Fortress
View of the ruins of Kastrum of the Tenth Legion from the remains of the fortress
Foundation of the principia (headquarters)