Background
There are two principal sources of information on Roman camps.
The primary purpose of a camp or fort was not to withstand attack but to provide a safe staging area
for troops to organize before deployment in battle. This is evident by towers being built-in or set flush
with the outside camp walls. Only in the twilight years of the empire, when its military might was
waning and it was being besieged by its enemies, did towers begin to protrude from fort walls to
improve the field of fire.
The typical legionary camp adhered to a playing card shape with rounded corners. It was surrounded
by a trench (fossa) with a mound (ager) crowned with a wall (vallum). The vallum in a marching
camp was a wood palisade but in permanent forts the defensive walls were of heavy timber or stone.
In the field, a legion would march for five hours before it halted. Engineers preceded the main body
and staked out a camp site. Upon arrival, the legionnaires would excavate the fossa, construct the
vallum, and erect their tents before dinner. On the day of departure breaking camp involved backfilling
the fossa to prevent occupation of the site by hostiles.
Camps, whether marching or permanent, were always constructed near a reliable source of water for
drinking and bathing. The engineers sited them on ground with sufficient slope to carry off waste
water. Latrines in permanent forts were specifically designed so that water flowed continuously
through them to carry off disease-causing effluent.
A cleared space (the intervallum) with a road (the via Sagularis, known as cloak street) paralleled
the vallum around the interior. The intervallum reduced vulnerability to incoming fire (viz.
incendiaries) by distancing the tents from enemy projectiles. It also provided a rallying/marshalling
point for troops to defend the ramparts or march out on patrol.
Unlike modern armies, there was no central mess hall. It was the responsibility of each
contubernium (a section of 6-10 men) to requisition food and cook their own meals (usually over
open fires in marching camps). In permanent forts or fortresses communal beehive-shaped ovens
were often recessed into the ager that bordered the intervallum.
Each castra was equipped with four gates defended by towers. The main gate (Porta Praetoria) was
typically oriented to face the direction of maximum danger. From this gate the via Praetoria ran
straight to a T-shaped junction where it intersected with the via Principalis (which had gates at either
end, the Porta Principalis Sinistra (left) and the Porta Principalis Dextra (right).
Roads were elevated in the centre so that surface water ran off into gutters flanking either side (and
thence out of the camp).
The via Praetoria stopped in front of the principia (legion headquarters). Directly behind the principia
the road continued under the name of the via Decumana (derived from the location of the 10th
maniple in a Republican camp) and ran to the rear gate (Porta Decumana). Since camp supplies
were received by way of the Porta Decumana, it was alternatively known as the Porta Quaestoria.
Parallel to the via Principalis and directly behind the Principia was the via Quintana (5th street)
which was on occasion equipped with gates where it met the ramparts at either end.
Internal Camp Structure
The via Principalis and the via Quintana split the camp into three sections. The physical location of
the barracks, the principia and the tribune’s houses was generally fixed in a camp.
The Praetentura:
The zone in front of the principia housed cohortal barracks. Quarters for the senior officers (above the
level of centurion but below that of legate) ran along the via Principalis. Cleanliness was important to
Romans and every permanent camp had baths within its walls or in close proximity outside. Baths
usually had an exercise hall and a courtyard for sports (a palaestra) not unlike a modern YMCA.
The Latera Praetorii:
This area was between the via Principalis and the via Quintana. To one side of the principia was the
commanding officer’s quarters (the praetorium). In a permanent fort it was a separate building
constructed in the fashion of a Mediterranean villa. The tribunal, altars, auguries [auguratorium],
granaries [horraea], the armoury [armamentarium], workshops [fabrica], the hospital
[valitudinarium], the legionary cavalry barracks [equites] and scouts [speculatores], were also
located in the latera praetorii.
The Rententura
Located at the rear of the camp, this area generally consisted of cohortal barracks, granaries and
stores.
There are two principal sources of information on Roman camps.
- Polybius (ca. 200 to 118 BC), an Achaean, who described contemporary camps in (chapters
19-42 of Book 6) Histories. He was a tutor to the Scipio family and accompanied Scipio
Aemilianus (a natural son of Aemilius Paullus) to the siege of Carthage in 146 BC. - Pseudo-Hyginus , an unknown author who composed De Munitionibus Castrorum, a work
on military camps, sometime between the 2nd and 4th century.
The primary purpose of a camp or fort was not to withstand attack but to provide a safe staging area
for troops to organize before deployment in battle. This is evident by towers being built-in or set flush
with the outside camp walls. Only in the twilight years of the empire, when its military might was
waning and it was being besieged by its enemies, did towers begin to protrude from fort walls to
improve the field of fire.
The typical legionary camp adhered to a playing card shape with rounded corners. It was surrounded
by a trench (fossa) with a mound (ager) crowned with a wall (vallum). The vallum in a marching
camp was a wood palisade but in permanent forts the defensive walls were of heavy timber or stone.
In the field, a legion would march for five hours before it halted. Engineers preceded the main body
and staked out a camp site. Upon arrival, the legionnaires would excavate the fossa, construct the
vallum, and erect their tents before dinner. On the day of departure breaking camp involved backfilling
the fossa to prevent occupation of the site by hostiles.
Camps, whether marching or permanent, were always constructed near a reliable source of water for
drinking and bathing. The engineers sited them on ground with sufficient slope to carry off waste
water. Latrines in permanent forts were specifically designed so that water flowed continuously
through them to carry off disease-causing effluent.
A cleared space (the intervallum) with a road (the via Sagularis, known as cloak street) paralleled
the vallum around the interior. The intervallum reduced vulnerability to incoming fire (viz.
incendiaries) by distancing the tents from enemy projectiles. It also provided a rallying/marshalling
point for troops to defend the ramparts or march out on patrol.
Unlike modern armies, there was no central mess hall. It was the responsibility of each
contubernium (a section of 6-10 men) to requisition food and cook their own meals (usually over
open fires in marching camps). In permanent forts or fortresses communal beehive-shaped ovens
were often recessed into the ager that bordered the intervallum.
Each castra was equipped with four gates defended by towers. The main gate (Porta Praetoria) was
typically oriented to face the direction of maximum danger. From this gate the via Praetoria ran
straight to a T-shaped junction where it intersected with the via Principalis (which had gates at either
end, the Porta Principalis Sinistra (left) and the Porta Principalis Dextra (right).
Roads were elevated in the centre so that surface water ran off into gutters flanking either side (and
thence out of the camp).
The via Praetoria stopped in front of the principia (legion headquarters). Directly behind the principia
the road continued under the name of the via Decumana (derived from the location of the 10th
maniple in a Republican camp) and ran to the rear gate (Porta Decumana). Since camp supplies
were received by way of the Porta Decumana, it was alternatively known as the Porta Quaestoria.
Parallel to the via Principalis and directly behind the Principia was the via Quintana (5th street)
which was on occasion equipped with gates where it met the ramparts at either end.
Internal Camp Structure
The via Principalis and the via Quintana split the camp into three sections. The physical location of
the barracks, the principia and the tribune’s houses was generally fixed in a camp.
The Praetentura:
The zone in front of the principia housed cohortal barracks. Quarters for the senior officers (above the
level of centurion but below that of legate) ran along the via Principalis. Cleanliness was important to
Romans and every permanent camp had baths within its walls or in close proximity outside. Baths
usually had an exercise hall and a courtyard for sports (a palaestra) not unlike a modern YMCA.
The Latera Praetorii:
This area was between the via Principalis and the via Quintana. To one side of the principia was the
commanding officer’s quarters (the praetorium). In a permanent fort it was a separate building
constructed in the fashion of a Mediterranean villa. The tribunal, altars, auguries [auguratorium],
granaries [horraea], the armoury [armamentarium], workshops [fabrica], the hospital
[valitudinarium], the legionary cavalry barracks [equites] and scouts [speculatores], were also
located in the latera praetorii.
The Rententura
Located at the rear of the camp, this area generally consisted of cohortal barracks, granaries and
stores.
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