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Templeborough Roman Fort in South Yorkshire visualised 3D flythrough, produced for Rotherham Museums and Archives.

In the Roman Republic and the Roman Empire, the Latin word castrum[1] (plural castra) was a building, or plot of land, used as a fortified military camp. In English, the terms Roman fort, Roman camp and Roman fortress are commonly used for castrum. However, scholastic convention tends toward the use of the words fort, camp, marching camp and fortress as a translation of castrum.[2]

Castrum was the term used for different sizes of camps including a large legionary fortress, smaller forts for Cohorts or Auxiliaries, temporary encampments, and "marching" forts. The diminutive form castellum was used for fortlets,[3] typically occupied by a detachment of a cohort or a century.

For a list of known castra see List of castra.



Castrum appears in Oscan and Umbrian, two other Italic languages, suggesting an origin at least as old as Proto-Italic language.

Julius Pokorny [4] traces a probable derivation from *k̂es-, schneiden (“cut”) in *k̂es-tro-m, Schneidewerkzeug (“cutting tool”).

These Italic reflexes based on *kastrom include Oscan castrous (genitive case) and Umbrian castruo, kastruvuf (accusative case). They have the same meaning, says Pokorny, as Latin fundus, an estate, or tract of land. This is not any land, but is a prepared or cultivated tract, such as a farm enclosed by a fence or a wooden or stone wall of some kind. Cornelius Nepos uses Latin castrum in that sense: when Alcibiades deserts to the Persians, Pharnabazus gives him an estate (castrum) worth 500 talents in tax revenues.[5] This is a change of meaning from the reflexes in other languages, which still mean some sort of knife, axe, or spear. Pokorny explains it as ’Lager’ als ‘abgeschnittenes Stück Land’, “a lager, as a cut-off piece of land.”

If this is the civilian interpretation, the military version must be “military reservation,” a piece of land cut off from the common land around it and modified for military use. All castra must be defended by works, often no more than a stockade, for which the soldiers carried stakes, and a ditch. The castra could be prepared under attack within a hollow square or behind a battle line. Considering that the earliest military shelters were tents made of hide or cloth, and all but the most permanent bases housed the men in tents placed in quadrangles and separated by numbered streets, one castrum may well have acquired the connotation of tent.[6]

Linguistic development of the military castraEdit

The commonest Latin syntagmata (here phrases) for the term castra are:

castra stativa
Permanent camp/fortresses
castra aestiva
Summer camp/fortresses
castra hiberna
Winter camp/fortresses
castra navalia or castra nautica
Navy camp/fortresses

In Latin the term castrum is much more frequently used as a proper name for geographical locations: e.g., Castrum Album, Castrum Inui, Castrum Novum, Castrum Truentinum, Castrum Vergium. The plural was also used as a place name, as Castra Cornelia, and from this comes the Welsh place name prefix caer- and English suffixes -caster and -chester; e.g., Winchester, Lancaster.

Castrorum Filius, "son of the camps," was one of the names used by the emperor Caligula and then also by other emperors.

Castro, also derived from Castrum, is a common Spanish family name as well as toponym in Italy, the Balkans and Spain and other Hispanophone countries, either by itself or in various compounds such as the World Heritage Site of Gjirokastër (earlier Argurokastro).

The terms stratopedon (army camp) and phrourion (fortification) were used by Greek language authors to translate castrum and castellum, respectively.



A castrum was designed to house and protect the soldiers, their equipment and supplies when they were not fighting or marching.

This most detailed description that survives about Roman military camps is De Munitionibus Castrorum, a manuscript of 11 pages that dates most probably from the late 1st to early 2nd century AD.[7]

Regulations required a major unit in the field to retire to a properly constructed camp every day. "… as soon as they have marched into an enemy's land, they do not begin to fight until they have walled their camp about; nor is the fence they raise rashly made, or uneven; nor do they all abide ill it, nor do those that are in it take their places at random; but if it happens that the ground is uneven, it is first levelled: their camp is also four-square by measure, and carpenters are ready, in great numbers, with their tools, to erect their buildings for them."[8] To this end a marching column ported the equipment needed to build and stock the camp in a baggage train of wagons and on the backs of the soldiers.


More permanent camps were castra stativa (standing camps). The least permanent of these were castra aestiva or aestivalia, "summer camps", in which the soldiers were housed sub pellibus or sub tentoriis, "under tents".[10] Summer was the campaign season. For the winter the soldiers retired to castra hiberna containing barracks and other buildings of more solid materials, with timber construction gradually being replaced by stone.[11]


The largest castra were legionary fortresses built as bases for one or more whole legions.[12][13]

From the time of Augustus more permanent castra with wooden or stone buildings and walls were introduced as the distant and hard-won boundaries of the expanding empire required permanent garrisons to control local and external threats from war-like tribes. Previously, legions were raised for specific military campaigns and subsequently disbanded, requiring only temporary castra. From then on many castra of various sizes were established many of which became permanent settlements.

Plan of fortsEdit

Plan of a typical Roman fort.
Reconstructed gateway of a Castrum Stativum at Arbeia (South Shields). Note the battlements, the Roman arches, the turres.

Sources and originsEdit

From the most ancient times Roman camps were constructed according to a certain ideal pattern, formally described in two main sources, the De Munitionibus Castrorum and the works of Polybius.[15] P. Fl. Vegetius Renatus has a small section on entrenched camps as well. The terminology varies but the basic plan is the same.[16] The hypothesis of an Etruscan origin is a viable alternative.[17]


The reconstructed porta praetoria of Castrum Pfünz, Germany, near the Rhaetian Limes.


The street plans of various present-day cities still retain traces of a Roman camp, for example Marsala in Sicily, the ancient Lilybaeum, where the name of the main street, the Cassaro, perpetuates the name "castrum".

Wall and ditchEdit

Castrum at Masada. Note the classical "playing-card" layout.

The Castrum's special structure also defended from attacks.




Streets, gates and central plazaEdit

Reconstructed east gate of a Castrum Stativum, a more permanent base, at Welzheim, Germany.
Porta called Savoia, Susa, Piedmont, 275-290 BC.

Every camp included "main street", which ran unimpeded through the camp in a north-south direction and was very wide. The names of streets in many cities formerly occupied by the Romans suggest that the street was called cardo or cardus maximus. This name applies more to cities than it does to ancient camps.[19]


On one side of the praetorium was the quaestorium, the building of the quaestor (supply officer). On the other side was the forum, a small duplicate of an urban forum, where public business could be conducted. Along the Via Principalis were the homes or tents of the several tribunes in front of the barracks of the units they commanded.



Porta Decumana at Weißenburg, Bavaria, Germany


On the other side of the praetorium the Via Praetoria continued to the wall, where it went through the Porta Decumana. In theory this was the back gate. Supplies were supposed to come in through it and so it was also called, descriptively, the Porta Quaestoria. The term Decumana, "of the 10th", came from the arranging of manipuli or turmae from the first to the 10th, such that the 10th was near the intervallum on that side. The Via Praetoria on that side might take the name Via Decumana or the entire Via Praetoria be replaced with Decumanus Maximus.[20]



Major buildingsEdit

Model of the legionary fortress of Deva (Chester) plus adjoining amphitheatre in Britannia (reconstruction).


Roman artillery piece (Onager)













Reconstructed barracks of a Castra Hiberna, or "winter camp", at Arbeia (South Shields). Each doorway provides entry to a large room, the sleeping quarters of one contubernium, or "squad" of about 10 men.



Modifications in practiceEdit




Quadrangular camps in later timesEdit

Many settlements in Europe originated as Roman military camps and still show traces of their original pattern (e.g. Castres in France, Barcelona in Spain).[23] The pattern was also used by Spanish colonizers in America following strict rules by the Spanish monarchy for founding new cities in the New World.

Many of the towns of England still retain forms of the word castra in their names, usually as the suffixes "-caster", "-cester" or "-chester" – Lancaster, Tadcaster, Worcester, Gloucester, Mancetter, Uttoxeter, Colchester, Chester, Manchester and Ribchester for example. Castle has the same derivation, from the diminutive castellum or "little fort", but does not usually indicate a former Roman camp. Whitley Castle however is an exception, referring to the Roman fort of Epiacum in Northumberland.

Camp lifeEdit



Ordinary lifeEdit

The pillars supported a raised floor to keep food dry and free from vermin in this granary at Housesteads Roman Fort (Vercovicium) on Hadrian's Wall.

Ordinary camp life began with a buccina call at daybreak, the first watch of the day. The soldiers arose at this time and shortly after collected in the company area for breakfast and assembly. The centurions were up before them and off to the principia where they and the equites were required to assemble. The regimental commanders, the tribunes, were already converging on the praetorium. There the general staff was busily at work planning the day. At a staff meeting the Tribunes received the password and the orders of the day. They brought those back to the centuriones, who returned to their company areas to instruct the men.

For soldiers, the main item of the agenda was a vigorous training session lasting about a watch long. Recruits received two, one in the morning and one in the afternoon.[25] Planning and supervision of training were under a general staff officer, who might manage training at several camps. According to Vegetius, the men might take a 32 kilometres (20 mi) hike or a 6–8 kilometres (3.7–5.0 mi) jog under full pack, or swim a river. Marching drill was always in order.

Each soldier was taught the use of every weapon and also was taught to ride. Seamanship was taught at naval bases. Soldiers were generalists in the military and construction arts. They practiced archery, spear-throwing and above all swordsmanship against posts (pali) fixed in the ground.[25] Training was taken very seriously and was democratic. Ordinary soldiers would see all the officers training with them including the praetor, or the Emperor, if he was in camp.



An aureus of the late republic


Another feature of the camp was the military hospital (valetudinarium, later hospitium). Augustus instituted the first permanent medical corps in the Roman army. Its physicians, the medici ordinarii,[28] had to be qualified physicians. They were allowed medical students, practitioners and whatever orderlies they needed; i.e., the military hospitals were medical schools and places of residency as well.[29]


Military service was for about 25 years. At the end of that time, the veteran was given a certificate of honorable discharge (honesta missio). Some of these have survived engraved on stone. Typically they certify that the veteran, his wife (one per veteran) and children or his sweetheart were now Roman citizens, which is a good indication that troops, which were used chiefly on the frontier, were from peoples elsewhere on the frontier who wished to earn Roman citizenship. However, under Antoninus Pius, citizenship was no longer granted to the children of rank-and-file veterans, the privilege becoming restricted only to officers.[31]

Veterans often went into business in the communities near a base.[32] They became permanent members of the community and would stay on after the troops were withdrawn, as in the notable case of Saint Patrick's family.


The remains of a granary at Housesteads Roman Fort on Hadrian's Wall.





  • guarding, cleaning and maintaining the principia.
  • guarding and maintaining the quarters of each tribune.
  • tending the horses of each cavalry turma.
  • guarding the praetorium.[33]

See alsoEdit


  1. ^ A 2nd declension neuter noun. According to Lewis & Short, dictionary item linked in External links, General, either the singular or plural was used, castra with a possible meaning of tents.
  2. ^ Campbell 2009, p. 4. Included is a discussion about the typologies of Roman fortifications.
  3. ^ See Vegetius, Epitoma rei militaris, 3.8. In Clark's translation, 3.8 is "Rules for Encamping an Army," last paragraph. "Small fort" is castellum, which Vegetius explains is the diminutive of castra. He conceives of them as fortified outposts to be manned by cavalry protecting a supply route; i.e., a base from which to conduct patrols.
  4. ^ Pokorny, Julius (1959). Indogermanisches Etymologisches Wörterbuch (in German). 2. Bern: Francke. p. 586.
  5. ^ Nepos, Cornelius. "Alcibiades 9.3". Latin Library.
  7. ^ Campbell, Duncan B. (2009). "A Camp in search of a Campaign: The reality of Hyginus' Roman army". Ancient Warfare. 3 (3): 46–49. Retrieved 18 April 2019.
  12. ^ Roman Legionary Fortresses 27BC-378AD, D.B.Campbell, Osprey.
  13. ^ M. C. Bishop, Handbook to Roman Legionary Fortresses, Pen & Sword, Hbk 208 pp ISBN 9781848841383
  24. ^ Roby under Secondary sources below.
  25. ^ a b Vegetius Book I, linked in Primary sources below.
  29. ^ Scheidel page 14 under External links, Camp life.
  30. ^ Scheidel pages 2-8 under External links, Camp life.

Primary sourcesEdit

Secondary sourcesEdit

External linksEdit



Forts and fortificationsEdit

Camp lifeEdit