Transactions of the Cumberland & Westmorland Antiquarian & Archaeological Society (Volume vol 14 no 1) online

people came not from a Roman general or statesman, but
from a German chief, Ariovistus, king of the Suevi. :: So
too it was a Parthian king, Phraates, who first proposed
that the Euphrates should be the dividing line between
the Republic of Rome and the kingdoms of the East.t



* Caesar, Bell. Gall., iv., 16.
t Plutarch. Pompey, 33.

But



THE ROMAN FRONTIER SYSTEM. 171

But the reply of Rome was in each case a refusal to
accept any limit to her career of conquest. Nor if the
Republican government had wished to trace and guard
the frontier lines of the empire would it have been easy
for it to do so. The empire as yet was not so much a
single state as a federation of states under the leadership
of Rome, and as a rule its only frontiers were those of the
allied states, — frontiers neither drawn by Rome nor de-
fended by her. Even where the limits of a Roman
province, that is of Roman territory, touched the confines
of barbarism, these limits were very often left vague and
ill-defined. There was a Roman " sphere of influence "
to use a modern phrase, but this sphere Rome was in no
hurry to limit, by too precise a definition.* We are told
indeed that Scipio marked the bounds of the old province
of Africa by a ditch, t traces of which existed in the time
of Vespasian,! but this ditch, merely separated the
Roman province from the allied state of Numidia, and
was itself probably of Carthaginian origin. § It must
lastly be remembered that the Republican government
had neither a permanent army, nor permanent camps,
and that with its numerous and changing proconsuls,
each independent of his colleagues and to a great extent
of the authorities at home, no uniform or continuous
frontier policy was possible.

The foundations of a frontier system were laid by
Augustus. It was he who organised the Roman army as
a standing force, who stationed the greater part of it in
the frontier districts, and who first established permanent
camps ; and though in the earlier years of his reign the



* Such was the case with the northern frontier of the province of Macedonia,
Cicero in Pison. 16, and with the western frontier of Hither Spain.

t Pliny, N. Hist 5. 25.

+ A recently discovered inscription (L'Annee Epigraphique (1S95) No. 65), of
Vespasian's reign refers to this ditch.

§ Midler. Fragm. Hist. Graec, 3, G22.

Old



172 THE ROMAN FRONTIER SYSTEM.

old ideas of universal empire found expression in litera-
ture,* and were possibly shared by himself, he left as a
legacy to his successors the advice " to keep the bounds
of the empire within fixed limits."!

But it was only the foundations that were laid by
Augustus. At the close of his reign, in many parts of the
empire, the districts organised as Roman provinces, and
garrisoned by Roman troops, were separated from the
" nations outside," " the peoples," to quote Seneca,
" among whom our peace ceases," by a broad belt of native
allied states, X and even where, as on the lower Rhine, a
real Roman frontier line had been drawn ; its intention
was rather to set bounds to the Roman advance than to
arrest invading barbarism. §

Augustus' immediate successors did little or nothing
for the actual construction of the frontier system, but
they undoubtedly paved the way for such an achievement
by the gradual annexation of the frontier native states of
Cappadocia, Pontus, Thrace, and Mauretania. Roman
territory was thus carried up to the political limits of
Roman authority.

The real authors of the frontier system were the Flavian
and Antonine Emperors, and the period extending from
the accession of Vespasian to the death of Marcus Aurelius,
or roughly from 70 A.U. to 180 A.D., witnessed its com-
plete organisation. The interest of these emperors in the
matter was no doubt quickened by the growing anxiety,
an anxiety unknown to the Augustan age, but perceptible
in Tacitus, as to the increasing pressure from without



* Horace, Od. 3, 3, 45.

t Tac. Ann. 1. 1 1.

J e.g., in the east, where the native states of Pontus, Cappadocia, and
Commagene lay between the most eastern Roman provinces and the Euphrates.

§ Tacitus. Hist. 4. 21, 23 explains the weakness of the camp at Vetera,by pointing
out that Augustus never contemplated the possibility of its being attacked by the
Germans.

upon



THE ROMAN FRONTIER SYSTEM. I 73

upon the empire.* At the same time it was only natural
that emperors, the keynote of whose policy was the
consolidation of the empire, and who gave it a singie
administrative system, a uniform franchise, and a uniform
municipal law, should have given it also well-defined
frontiers, and a comprehensive system of defence. It
would be out of place here to describe in detail the
accomplishment of the task, or to assign to each emperor
his proper share of the work, but it is well for students of
the British frontier to remember that the emperor with
whose name the organisation of the imperial frontier
system is most closely connected is Hadrian.

The real motive for his restless travelling, was not the
curiosity of a connoisseur, but the resolution of a great
ruler to set in order the defences of the empire. Each
frontier was visited in turn, the military posts inspected,
and the troops reviewed. Of one such visit, a memorial
remains in the extant fragments of his speech to the army
in Africa, which were found on the site of the central
camp constructed by his orders for the famous Third
Legion at Lambaesis. t We can read the words of
commendation which he bestows on the legion for the
skill shown in the construction of the camp, and for the
high state of efficiency which had been maintained in
spite of the fact that it had been rarely possible to drill
the men together owing to the number always absent on
detachment duty in the frontier posts. The auxiliary
cohorts and squadrons are similarly praised for the
manner in which they had performed their exercises, and
exhorted to constant practice in the use of their arms.
From quite another quarter of the empire comes a valu-
able supplement to these words of Hadrian himself.



* The difference of tone as between Horace and Tacitus is very marked and
has often been noticed.

fCorp. Inscr. Lat. VIII. 2532.

Fortunately



174 THE ROMAN FRONTIER SYSTEM.

Fortunately we still possess the report made to Hadrian by
his legate Arrian, lieutenant governor of the north eastern
frontier province of Cappadocia, on the stations and
garrisons along the south-eastern coast of the Black Sea.*
Arrian describes how he inspected the camps ; he reports
the replacement of earthern banks and wooden towers by
solid masonry, and everywhere he put the garrisons
through a variety of movements and exercises. If to
these two direct testimonies we add the many other
proofs which exist of Hadrian's activity on the frontiers,
we shall be justified in regarding him as the man to
whom the imperial frontier system mainly owed its
marvellous completeness and uniformity.

We may then take this frontier system as the work of a
single century, inspired by one policy and executed on a
single plan ; let us examine it more in detail.

The terms used to denote the frontiers were " limes "
or its plural " limites," and it is worthy of notice that the
use of these terms to designate the imperial frontiers,
begins as we should expect, towards the close of the first
century A.D. with Frontinus and with Tacitus. To the
latter we owe in particular the phrase " limes imperii."!

This use of the term " limes " in the sense of a frontier
or march flowed naturally from the original meaning of
the word. " Limites "' were properly the raised balks
dividing the separate allotments in an area measured out
and assigned according to strict Roman rules. Along the
top of these balks ran paths or narrow roads. The
" limes" was thus at once a boundary and a road, and in
the literature of the Ciceronian and Augustan ages, it is
popularly used in both senses. X But its meaning as a



* Arrian, Periplus Pont. Euxini.

t Frontinus. Strateg. i, 3, 10, limitibus per cxx, M.P. actis. com p. 2, 11, 7.
Tac. Germ. 29. limite acto, promotis prsesidiis. lb. Agric. 41 de limite imperii et
ripa.

* Yirg. Aen, 9, 323, lato te limite ducam. Horace Od. 2, iS, 25, ultra limites
clientium salis avarus.

boundary



THE ROMAN FRONTIER SYSTEM. T75

boundary gradually predominated, and it was in this
sense that the term was applied to the imperial frontiers.
Professor Mommsen has, however, ingeniously endea-
voured to show * that these imperial " limites " remained
true in their form to the original idea, and that each
consisted of a strip of land with clearly marked bounds
on both sides and with a road running along it. It is
enough to say here that his application of this theory to
the extant frontier lines in Britain and Germany does not
appear to be successful. I cannot believe that our own
stone wall and vallum represent the outer and inner
edges of the British limes, and as to the road, the only
certain Roman road running parallel with the frontier
line is south of the vallum, t In the case of the
Grahame's Dyke, and the Pfahlgraben, he has to confess
that while an outer boundary can be found, no inner
line of demarcation has yet been discovered. At the
same time there is no doubt that " limes " like " march "
was frequently used to include not only the frontier line
with its defences, but the territory stretching along both
sides of it.

The first step in the construction of a frontier must
have been delimitation : where the line should be drawn
and what course it should follow, were matters which a
variety of considerations might decide. In some cases a
river supplied an obvious and natural boundary ; where
no river existed, and an artificial line had to be traced,
the surveyors were probably guided by existing territorial
divisions or by the limits of Roman settlements, as was
possibly the case in upper Germany, or as in Africa, by
the limits of cultivable or habitable land, or finally by
simple convenience.

We must assume further that the course of the frontier



* West Deutsche Zeitschrift.
f The " Stanegate."

line



jyG THE ROMAN FRONTIER SYSTEM.

line was marked in some visible way. Mommsen rightly
urges that an underground concealed ditch, such as that
recently found in Germany, must have been supplemented
by some indications of its course above ground. The
difficulty would plainly arise only where, to quote Spar-
tianus,* the barbarians were separated not by rivers but
only by limites. How it was solved is uncertain, possibly
in some cases by boundary stones at short intervals, but
very possibly also by a continuous bank and fosse t ; and
such may have been the nature of the limites which
Hadrian rendered more difficult of passage by palisades. £
It is dangerous to dogmatise about the British vallum,
but Mr. Haverfield's suggestion that it represents such a
line of delimitation, as distinct from the military line of
defence is at least plausible.

Delimitation must have been accompanied, or very
shortly followed by defence, sufficient at any rate to
ensure that the frontier was respected, to check raids or
smuggling, and to regulate the ordinary traffic. Obviously
the line of defence would not always coincide exactly with
the line of delimitation. It might be in advance of it, or
just to the rear of it, or might cross and recross it. Its
strength too would vary with circumstances.

But in all cases known to us, the line of defence along
a Roman frontier was formed by a chain of military posts.
The distances between the posts varies greatly, as does
their relation to the frontier line, but the chain of posts
is universal. The posts themselves are very uniform in
type. Except along the lower Rhine, the Danube, and
the upper Euphrates, the camps of the legions do not



* Vit. Hadriani, 12.

t Hyginus (ed. Lachmann), p. 192, multi perpetuos limites egerunt, sicut in
veterum coloniarum finibus invenimus, frequentius in provinces. It appears
from the African inscription referred to above that in Vespasian's delimitation of
the province of Africa, boundary stones were only used "qua fossa afuit " where
there was no ditch.

X Vit. Hadr. 12.

form



THE ROMAN FRONTIER SYSTEM. 1JJ

form part of the chain, but are planted at some consider-
able distance to the rear. This is so in Britain, in Africa,
and in Upper Germany. York, Chester, Lambessa, Mainz,
and Strassbourg serve as supports to the frontier posts
and are connected with them by roads. The posts which
actually constituted the links in the chain of defence
were generally known as " praesidia." But they could
also be classified according to their size as " castella,"
" burgi," and " turres." These three grades of posts we
in England have rechristened " stations," " milecastles,"
and " turrets," a difference of terminology which rather
obscures the uniformity of the system. Everywhere the
"burgi" and "turres" seem to have served as stations
for signalling and observation, and are placed at intervals
between the larger camps, — the " castella. " ;:

In two well-known cases at least, the line of defence
formed by the fortified^posts was further strengthened by
a connecting wall or earthern rampart. But such a
continuous barrier as our British wall, or the German
Pfahlgraben, was not an invariable element in the frontier
system. It was clearly superfluous where a great river
afforded security, as on the lower Rhine, the Danube, or
the'Euphrates, nor is there any evidence of its existence
along the African frontier.

In several cases the chain of posts is not single, but
double or even treble. It is so in Upper Germany, f
along some sections of the African frontier,]: and it must
have been so in Britain, during the brief period between
the erection and the abandonment of the " Vallum Pii."



* " Praetentura " and "clausura" are only found in late writers. Ammianus
( 14, 3), speaks of Mesopotamia as guarded " praetentuiis et stationibus agrariis."
Justinian (Cod. 1, 27), says of the African "limes" that its line was marked
" clausuris et burgis." In the Housesteads inscription Corp. 7,643, "praeten-
tura " probably bears its earlier meaning of a part of a camp.

â– f The original line was maiked by the Rhine, the second was that now known
as the " Neckar Mumling Linie," the third that of the Pfahlgraben.

+ Cagnat. L'Armee Romaine d'Afrique, gives a clear account of the three
successive linesidrawn along the south frontier.

In



I7S THE ROMAN* FRONTIER SYSTEM.

In the three cases mentioned, in Upper Germany, Africa,
and Britain, it seems almost certain that the doubling or
trebling of the lines of defence was primarily due to the
pushing forward of the frontier,* and to the fact that the
earlier line or lines were still garrisoned, even after the
construction of the new one. We are indebted to
Frontinust for a partial explanation, at any rate, of this
policy. Among the devices of strategy, which he com-
mends, is that by which a troublesome tribe was isolated
and cut off, not only from the peaceful borders of a Roman
province, but from the tribes in their rear, among whom
they might have found shelter and assistance. In this
way he says Domitian completely enclosed the marauding
tribes of the Taunus, and cut them off from their power-
ful allies the Chatti. It was no doubt with the same
object that in Africa, the mass of Mount Aures was
girdled round with Roman garrisons, and the language of
Pausanias, J as to the vallum of Pius suggests that the
intention here also was to isolate the turbulent tribes
lying between this barrier and the wall from their northern
kinsmen or allies.

An important feature in the frontier system was the
treatment of the land lying immediately beyond the line
of defence. Such land was cleared of its native population
and treated as part of the frontier, or march. Tacitus\>
mentiones such a belt of land along the further banks of
the lower Rhine, and adds that it was reserved for the
soldiery. Marcus Aurelius, after the Marcomannic war,
cleared a strip, varying from four to eight miles in breadth,
beyond the Danube. Xo barbarians might settle there,
except at the places an 1 on the days set apart for



* Zangemeister. Neue Heidelberg - . Jabrbuch, 1S95, while assigning the camps
on the Neckar line and on the Pfahlgraben to the same date ( Hadrian — Ant. Pius),
holds that the Neckar line represents an earlier frontier.

f Strategem, 1, 3, 10, and 2, 11, 7.

% Pausan, S, 43, o7rt rt/xtro . . . tCov JSpiyavTuv Trjv ttoAaj'/i/-

§ Tac. Annals, 13, 54.

occasional



THE ROMAN FRONTIER SYSTEM. 179

occasional markets on the riverside. * The outlying
posts not unfrequently found beyond the frontier may in
some cases have been intended to keep order in this
cleared border-land. But these posts also served the
purpose of guarding and keeping open the " lines of
attack," the roads that is along which an expeditionary
force would advance when sent to chastise a marauding
tribe, or quell a disturbance. Both these purposes may
have been served by such posts as those at Birrens,
Bewcastle, and High Rochester.

But the Roman frontier or march in its widest sense,
included, besides the cleared land in front, a certain area
of territory in the rear. The two together constituted
what in the fourth and fifth centuries was known as the
" terra limitanea " or " agri limitanei."t Of these border-
lands the emperor was lord. Here were the imperial
" saltus " administered by his " procurators," and culti-
vated by his coloni.| Portions of it were from time to
time granted to veterans, others were assigned to the
frontier soldiery, or in some cases to native tribesmen
or to settlers from within the empire. It is probable
however that in the second and third centuries, as in the
fourth and fifth, the obligation to assist in the defence of
the frontier was a condition of the tenure of such land.§



* Dio. 71, 14, 16. Very similar regulations exist on our own Indian frontier.

t Cod Theod 7, 15, Cod. Just, 1 1, 59.

I The frequency with which imperial "saltus" occur in the frontier districts
of Africa is noted by Cagnat. L'Armee Romaine d'Afrique. They are found also
in the territory between the Rhine and the Pfahlgraben. One existed near
Sumelocenna (Rotenburg), and extended up to and beyond the limes. A Greek
inscription mentions an imperial procurator Xwpag ^V/uieXoKevvi)