A Roman camp, fortified with a rampart and a ditch, outside of which a Roman army never
spent a single night. It was marked out on a place selected for the purpose, generally upon
the spur of a hill. The same plan was always observed, and the quarters were indicated by
coloured flags and lances, so that the divisions of the army, as they came in, could find
their places at once. In the middle of the second century B.C., according to the account of
Polybius (vi. 27), the plan of a camp for a consular army of two legions, with the proper
contingent of Italian allies and its auxiliary troops, was as follows (see plan): The
Plan of a Roman Camp. (After Polybius.)
camp was square, its front being on the side farthest from the enemy. It had two
main streets through it. (a
) The via principalis
100 feet wide, which divided it into a front part amounting to about two-thirds of the whole,
and a back part turned towards the enemy. This road ended at two gates: the porta principalis dextra
and the porta principalis sinistra. (b)
The via praetoria
, which cut the via principalis
right angles, and divided the whole length of the camp into two parts. This road was 50 feet
in width, and ended in two gates: the porta decumana
in front and the
on the side opening towards the enemy. In the front
part were encamped the two legions, with their allied contingents. They lay in three
double rows of tents on each side of the via praetoria
, which made a
right angle with the via principalis.
Its whole length was divided by
streets 50 feet in width, while across it, from one lateral rampart to the other, ran the
The front side of the rows of tents was turned towards
the intervening streets. Starting from the via praetoria
, the first two
lines of tents on each side contained the cavalry and infantry of one legion each, while the
third row, lying nearest to the rampart, contained the cavalry and infantry of the allied
contingents. In the hinder part of the camp, directly upon the via
, and on both sides of the via praetoria
, were the
tents of the twelve military tribunes, opposite the four ranks of the legions. On both sides
were the tents of the praefecti
of the allied contingents, placed in the
same way opposite those of the troops under their command. Then followed the headquarters, or
, a space 200 feet square, intersected by the via praetoria.
In this was the general's tent (tabernaculum
front was the altar on which the general sacrificed, on the left the augurale
for taking the auspices, and on the right the tribunal.
This was a bank of earth covered with turf, on which the general took his stand when
addressing the troops (see Adlocutio
administering justice. On the right of the praetorium
was the quaestorium
, containing the quarters of the paymasters and the train of
artillery. On the left was the forum
, a meeting-place for the soldiers.
Between these spaces and the lateral ramparts were the tents of the select troops who
composed the body-guard of the general. Those of the cavalry had their front turned inwards,
while those of the infantry were turned towards the wall. The tents of the picked allied
troops occupied the hinder part of the camp, which was bounded by a cross-road 100 feet in
breadth. The tents of the cavalry looked inwards, those of the infantry towards the rampart.
The auxiliary troops were posted at the two angles of this space. The rampart was divided
from the tents by an open space 200 feet in width. This was specially intended to facilitate
the march of the troops at their entrance and exit.
The construction of the fortifications always began before the general's tent was pitched.
The legionaries constructed the rampart and ditch in front and rear, while the allies did the
same on either side. The stakes required for the formation of an abattis
on the outer side of the wall were carried by the soldiers themselves on the
march. The whole work was carried on under arms. The watches (excubiae
) were kept with great strictness both by day and night. The
, or night-watches, were relieved four
times, the trumpet sounding on each occasion. The posts of each night-watch were inspected by
four Roman equites.
The password for the night was given by the general.
Each gate was guarded by outposts of infantry and cavalry, the lightarmed troops (velites
) being also distributed as sentries along the ramparts. When the
camp was to break up, three signals were given; at the first, the tents were taken down and
packed up; at the second, they were put upon beasts of burden and in wagons; and at the
third, the army began its march.
After the time of Polybius the Roman military system underwent many changes, which involved
alterations in the arrangements of the camp, but we have no trustworthy information on this
subject in detail until the beginning of the second century A.D. The treatise of Hyginus
(q.v.) on castrametation gives the following
statements as to the practice of his time. The ordinary form of a camp was that of a
rectangle, the length of which was about a third part greater than the breadth. In former
times the legions were posted inside the camp; but now, being regarded as the most
trustworthy troops, they were encamped along the whole line of ramparts, the width of which
was now limited to 60 feet. They were separated from the interior of the camp by a road 30
feet wide (via sagularis
), running parallel to the line of ramparts. The
interior was now divided, not into two, but into three main sections. The midmost of these
lay between the via principalis
, which was 60, and the via quintana
, which was 40 feet wide. It was occupied by the praetorium
and the troops of the guard, and was called the wing of the praetorium (latera praetorii)
. The auxiliary troops were stationed in what was now
the front part, or praetentura
, between the via
and the porta praetoria
, and the rear, or retentura
, between the via quintana
and the porta decumana.
The via praetoria
, which was also 60
feet wide, led only from the praetorium
and the forum
in front of it to the porta praetoria
, as at this time the
was situated between the porta
and the praetorium.
The general superintendence of the
arrangements was, during the imperial period, in the hands of the praefectus
All the important literature on the subject of camps will be found in the work of Marquardt
and Mommsen, v. 390-408.
Castra Praetoriāna. The permanent encampment on the
outskirts of Rome where the Praetorian Guard was stationed (Claud.
Castra Navalia. A line of fortifications drawn up around a fleet
to protect it from attack, when it was drawn up on the shore (B. G.
The term Castra Nautĭca is also used.