Marching or Temporary Camp

Temporary marching camps were created to protect the legions on the move. At the end of each day’s march a fortification was created that involved the digging of a large defensive ditch (fossa) and the building of a rampart (vallum) crowned by a palisade, around the four sides of the camp. According to the third-century Roman textbook, compiled from earlier sources, the camp (castra) was rectangular, and had rounded comers and a gate in each side; in the middle was the commanding officer's tent (praetorium), and the rest of the tents were laid out according to established rules. Within a network of streets based on two axes, the cardo and decumanus, crossing one another at right-angles at the entrance to the praetorium. 

These remains are especially numerous in the extremities of the country, that is, areas in which the Roman army was engaged in repeated and/or prolonged campaigns at different stages during the Roman involvement in Britain. Thus Scotland in general has many examples whereas the north of England has comparatively fewer and the south of England has very few indeed. Wales and the Marches is another region well populated with examples of such works, and more recently the south-western and eastern extremities of England have produced evidence for appreciable Roman military activity, including examples of temporary camps.

Groups of such works, no doubt often individually re-used, occur at important staging-points, such as Newstead (Trimontium) or Glenlochar.

The terrain in which a camp is planted is often, however, unsuited to the application of rigid rules, which are then varied in common-sense fashion. Thus, while rectangularity is aimed at and often achieved, it is quite often abandoned for the parallelogram or a much less regular figure. Again, while the medium-sized camp will have four gates, large camps will have six and sometimes more, and small ones may have two or even one only. But, however its shape may vary, a Roman camp is still normally bounded by straight lines. Whatever their number, and whatever the variations from the rectangle, the sides never show any appreciable curvature. The corners are always curved, the sides never. Even when a Roman camp departs widely from the norm and becomes an irregular polygon its sides are still approximately straight.

The gates, again, afford clear indications of Roman or non-Roman origin. With rare exceptions (Cawthorn Temporary Camp C is one, Raedykes Camp is another) they do not occur at the corners of a Camp, but in its sides. Radykes, like most Roman camps, is based upon rectangular planning, but the north and west sides are distorted so as to conform to the ground, while its main corners have no gates in them. To return to the general question, the gates of camps are of two main varieties: those defended by traverses and those defended curved extensions of the rampart or ditch, if not both. The De munitionibus castrorum indeed prescribes an external tutulus combined with an internal clavicula, but this is rare in practice, and the type of gateway most often found is that with a simple tutulus, which is a detached length of rampart and ditch forming an isolated work closing the line of direct entry to a gate.

Internal Arrangements of a Roman Camp

The internal arrangements of a camp are elaborately described in the De munitionibus castrorum. In the centre was the commanding officer's tent praetorium); this faced the porta praetoria, and gave on the via principalis, joining the porta principalis dextra and the porta principalis sinistra. Parallel to this street, and behind the praetorium, ran the via quintana, at whose ends gates might or might not be provided, depending upon the size of the camp. At the back was the porta decumana. The area in front of the via principalis is the praetentura, that behind the via quintana the retentura. To right and left of the praetorium lie the latera praetorii.

So far, most camps probably conformed pretty well to the rules. We generally find that a Roman camp is rectangular or shows obvious traces of being based on the rectangular plan, and that it has either four gates - two central in the ends, two placed in the sides or six. But how far the detailed disposition of tents always or generally followed theoretical practice we cannot say. It is, however, to be observed that at Reycross, where the disposition of gates permits subdivisions to be largely defined, the ten subdivisions associated with the ramparts will accommodate ten cohorts on the scale given by the De munitionibus castrorum. This allows a calculation of a camp of about 900 feet square to house a legion. Much of this ground is taken up with administrative quarters, officers' quarters, roadways, etc.; the striga or double row of soldiers' tents, together with its central street, occupies 190 by 180 feet. Assuming, as we must in the absence of other evidence, that this represents usual practice, we must allow about 300 men to the acre in Roman camps. The ratio in permanent forts was much more amply conceived.

On ground now cultivated, Roman camps are seldom visible on the surface; their relatively slight earthworks have been obliterated by the plough. Even here, however, digging will reveal their ditches, by showing a distinction in colour and texture between their filling and the undisturbed subsoil through which they have run. The moist silty soil composing the filling will also produce variations in the growth of crops readily perceptible from an aircraft and sometimes visible on the ground. and thus, even when completely levelled by cultivation, Roman camps have been detected by air photography in very large numbers. Without this aid, they can be seen from the ground only in uncultivated country, on moorlands and wastes untouched by the plough. Here their defences are seen as a mound, from 5 to 10 feet wide and from 1 to 2 feet high in the centre, and a ditch immediately outside it. The crucial test for the Roman origin of the works is provided by the form of the gateways.

Semi-permanent Camps

Another interesting type is the special and rare kind, known to archaeologists as 'semi-permanent', erected by troops for a siege, as at Bumswark (Dumfriesshire) (Plate III b), or for a lengthy yet temporary stay while engaged upon a task of duration, as at Chew Green (Northumberland). Here the works are more massive; the mound of the rampart may be 20 feet wide, or even more, and may still stand to a height of 10 feet above the ditch bottom, even before excavation. Apart from the gateways, which are usually provided with either claviculae or traverses, such remains are not easily distinguishable from permanent forts without digging. Yet the presence of claviculae or traverses at the gates generally indicates a camp and not a fort (a few forts have traverses, hardly any have claviculae): while the distinction between the massive rampart of a semi-permanent camp and the slight rampart of a temporary camp jumps to the eye.

In a semi-permanent camp the material composing the rampart may be (as at Cawthorn B) turf, instead of earth; it may (as at Cawthom B) expand at intervals into ballistaria, emplacements for artillery, and it may (as at Cawthorn A) contain remains of ovens, Inside a semi-permanent camp may be found 'dug-outs', latrine-trenches and small continuous mounds intended to keep wind and water out from under the flies of tents - all structures suitable to a camp occupied for more than a night or two.

A camp of this kind might serve as quarters for a force on practice-work (Cawthorn) or on construction work (Chew Green) and might as at Cawthorn B, even be reoccupied another year; whereas the earthern works of a temporary camp were so easy to construct that it would generally be more convenient to make a new camp, even for a single night, than to reoccupy an old. It must be borne in mind that a ditch 6 feet wide and 3 feet deep (a fair average size) surrounding such camp as Reycross, which in 184 acres contains about 6,000 men, represents the excavation of some 3,000 cubic yards of earth; so that even if only half of the men were employed in digging, each would have no more than a cubic yard of earth to move.

The earthworks of a camp, whether temporary or semi-permanent, did not constitute its only defence. On the contrary, their main purpose was to serve as a basis for some kind of palisade. In the case of a temporary camp, this consisted merely of stakes driven into the agger; the larger earth works of a semi-permanent camp supported more elaborate palisades, which might amount to a vertical timber revetment in front of a rampart, supported by posts and spurs, as at Cawthorn A, together with an embattled timber parapet, and a wooden 'duck-board parapet walk, as illustrated on Trajan's Column. When so elaborated the earth-and-timber rampart of the semi-permanent camp becomes indistinguishable from that of the earth-and-timber type of permanent fort. The palisade of the temporary camp, on the other hand, was a portable affair; each soldier carried not less than two stakes, formed of stout straight boughs with their branches trimmed and cut short, and these were used to make the palisade when camp was pitched. It may be observed that, in a work resembling Reycross, there would only be some seven running inches of rampart per man.

The ditch of a temporary camp is normally single, 4 to 10 feet wide, and 2 to 6 feet deep. In a few cases, whether because it is completely silted up or because the ground did not permit one to be dug, no trace of a ditch is now visible, e.g. at Bellshiel (Northumberland), Reycross (Yorkshire N.R.). Almost always the ditch is V-shaped or, as the textbook calls it, fastigata (gabled). The textbook also describes another type, the "Punic" which has its outer side vertical, but this seems to have been seldom used, and examples, at Hod Hill and Cawthorn D, are confined to forts. This kind of ditch was used at the outer edge of a field of fire, because its sloping inner side invited the enemy to cross it, while the vertical side trapped them on their return. It is called Punic because of its deceptive character. In a semi-permanent camp the ditch is larger, and, as at Cawthorn D, it may be double. Thus at Cawthorn A the rampart was found standing 7 feet high and 20 feet wide, and the ditch 15 feet wide and 8 feet deep when cleared out. The bottom of a fastigate ditch is normally formed by a small square channel; this, as shown by a half-finished example at Cawthorn A, is the bottom of a straight-sided trench, wide enough for a man to stand in, the sloping sides of the ditch being then formed by raking the earth down into a basket. In a camp, whether temporary or semi-permanent, there is little berm, or level space between ditch and rampart. A berm becomes necessary only when the earthen rampart is replaced or revetted by a heavy stone wall, which might crush the lip of the ditch; or when, conversely, the ditch is cut in soft subsoil liable to slip.

Locations of Marching or Temporary Camps in Roman Britain

Different Types of Marching or Temporary Camp