In Europe Britain have been omitted) The frontier in Britain existed from the 1st to the 5th century AD. Initially the Fosse Way road was a frontier. From the 1st to the 2nd century first the Gask Ridge and then the Stanegate, with their chains of forts and watchtowers, marked the northern boundary of
Britannia. Later
Hadrian's Wall was built as the frontier and for a short time the
Antonine Wall further north. The defence of Hadrian's Wall was achieved through the incorporation of
forts and
castella. Security and monitoring on the coasts in the west and southeast were achieved by forts and by chains of watchtowers or signal towers, both along the coastline. The garrisons,
Exercitus Britannicus, consisted mostly of
cohorts of
auxilia. The strategic reserve comprised three
legions based in
Eburacum (York),
Isca Silurum and
Deva. The observation and surveillance of the waters around the British Isles was the responsibility of the
Classis Britannica, whose headquarters were in
Rutupiae (Richborough). Legions, auxilia and the fleet were commanded by the provincial governors. From the 3rd century, units of
comitatenses, limitanei and
liburnaria (marines) came under the command of two generals: •
Comes Britanniarum •
Dux Britanniarum Saxon Shore This section of the
limes existed from the 3rd to 5th centuries AD and covered the provinces of: •
Britannia Inferior •
Belgica •
Lugdunensis •
Aquitania This
limes of the
Late Antiquity ran through the territory of the present-day
United Kingdom and
France. In the 3rd century, a separate military district, the
Litus Saxonicum, was established on the British side of the
English Channel between the estuaries of
the Wash and the
Solent, to repel
Saxon pirates and plunderers. The Gallic side of the English Channel and Atlantic coast were included therein. Monitoring and coastal surveillance were carried out by a chain of watchtowers or signal towers, forts and fortified ports (Gaul). Most of the Saxon Shore camps probably served as naval bases. The garrisons of the forts were composed of infantry and several cavalry regiments. Monitoring and surveillance of the Channel were the responsibility of the
Classis Britannica and
Classis Sambrica, whose headquarters were in
Locus Quartensis (Port d'Etaple), guarding the mouth of the
River Somme. The units of
comitatenses, limitanei and
liburnaria in this area came under the command of three generals: •
Comes litoris Saxonici per Britanniam (Count of the Saxon Shore) •
Dux Belgicae secundae •
Dux tractus Armoricani et Nervicani Lower Germania (Rhenish limes: between the Rhine and the Elbe) from the
1st century to the
5th century. Map of the legion camps and forts in Germania Inferior This section of
limes existed from the 1st to the 5th century AD and ran through the province of Lower Germania (
Germania Inferior). It lies on the territory of today's
Netherlands and
Germany. This
limes was a river border (
limes ripa) on the
Rhine, defended by a chain of
camps, that ran from the North Sea (Katwijk-Brittenburg camp) to Vinxtbach (opposite
Rheinbrohl fort on the
Upper Germanic Limes), forming the border between the Roman provinces of
Germania Inferior and
Germania Superior. By contrast with the
Upper Germanic-Rhaetian Limes, it was not marked by a solid palisade or wall. Neither can any
defensive ditch or
rampart be identified. The guards were stationed in nearby
castra and watchtowers usually built immediately on the Rhine. The
limes was served by a well-developed military road. Each camp had its own river port or landing stage and a storage area, because the Rhine not only formed the border but was also the most important transport and trade route in the region. In the first section, between the camps of
Rigomagus (Remagen) and
Bonna (Bonn), there were only a few camps. In the second, middle, section between
Bonna and
Ulpia Noviomagus Batavorum (Nijmegen), there were considerably more. Here there were also larger legion camps; with one exception, all were cavalry barracks. The landscape of the third section between
Ulpia Noviomagus Batavorum and
Mare Germanicum (the North Sea) was characterised by numerous small streams and boggy marshland. Consequently, in this area there was only one cavalry camp. Border security here consisted mainly of tightly packed, relatively small cohort forts. The occupying troops,
Exercitus Germaniae Inferioris, consisted mostly of auxilia cohorts. From the 2nd century, the strategic reserve comprised three legions stationed in
Bonna/Bonn,
Novaesium/Neuss,
Vetera/Xanten and
Noviomagus/Nijmegen. The control and surveillance of the waters of the North Sea, the Rhine estuary and the Lower Rhine was the responsibility of the
Classis Germanica whose headquarters was in
Colonia Claudia Ara Agrippinensium/Cologne. Legions, auxilia and fleet units were commanded by the respective provincial governor. From the 3rd century the
ripenses (river guards),
comitatenses, and
liburnaria were under the command of the
Dux Belgicae secundae.
Upper Germania and Rhaetia This
limes existed from the 1st to 5th centuries AD and guarded the provinces of: •
Germania Superior •
Rhaetia It lay on the territory of the present German states of
Rhineland-Palatinate,
Hesse,
Baden-Württemberg and
Bavaria. To the north, it bordered those parts of the Roman province of
Rhaetia that lay north of the
Danube and guarded the eastern border of that part of
Germania Superior that lay east of the Rhine. In Upper Germania the border defences initially consisted only of a post road. From about 162/63 AD, the Romans constructed a defensive barrier with watchtowers and signal towers,
palisades, ditches and earthworks. On one short section of the Rhaetian Limes, a solid stone wall was erected. In its final stages, the Upper Germanic-Rhaetian Limes was about 550 kilometres long and ran from
Rheinbrohl, in the county of
Neuwied in northern Rhineland-Palatinate, as far as
Hienheim on the Danube. Between the villages of
Osterburken and
Welzheim, the
limes ran for 81 kilometres almost in a straight line southwards.
Noricum This section of the
limes existed from the 1st to the 5th century AD and guarded part of the Roman province of
Noricum. It is on the soil of the present-day Austrian states of
Upper and
Lower Austria. It ran along the
Danube from Passau/
Boiodurum to Zeiselmauer/
Cannabiaca. This is also a
ripa (river border), which was guarded by a loose chain of cohort forts. The main road on the Norican Limes was the
via iuxta amnem Danuvium. The initially simple wood and earth structures were systematically converted under Emperor
Hadrian into stone encampments. During the 4th century, they were brought once more up to date and massively reinforced. Between the camps, in strategic places or good points of observation, were watchtowers or signal towers and, in the Late Antiquity,
burgi. In the middle section, between the camps of
Favianis and
Melk, watchtowers were built only sporadically. Here the narrow valley of the
Wachau, with its densely forested escarpments, made access to the riverbank more difficult, providing some defensive function. Every camp had its own river port or landing stage and a storage area because the Danube was not only a border zone, but also the most important transport and trade route in the region. Over time civilian settlements or
vici were established immediately next to the camps. In the immediate hinterland of the
limes, walled towns or
municipia were founded – for example,
Aelium Cetium or
Ovilava (Wels). They were the administrative or commercial centres of the region. In late antiquity, the Norican area was divided into two parts (
pars inferior and
pars superior).
Pannonia This stretch of
limes was in use from the 1st to the 5th centuries AD and helped to guard the provinces of: •
Pannonia inferior •
Pannonia The
Pannonian Limes is situated on the territory of present-day Austria,
Slovakia and
Hungary. Although this section of the frontier was relatively well protected by the Danube river border or
Ripa, the Roman military presence here was always exceptionally strong (three military camps in Pannonia, but only one in Lower Pannonia) because especially after the abandonment of
Roman Dacia in the late 3rd century, the pressure of migrant peoples from the east on this section of the
limes intensified. The tributaries emptying into the Danube offered cheap transport routes, but also made good approach routes for invaders and raiders. The military camps were therefore built by the most important fords or confluences and road termini. The legion- and auxilia camps were mainly located in the immediate vicinity of the riverbank. The initial wood and earth structures, were systematically converted under Emperor
Hadrian into stone barracks and, in the 4th century, redesigned and massively strengthened in order to match new strategic requirements. The gaps between the camps were closed by a chain of watchtowers or signal towers. In late Roman times huge
inland camps were built and towns in the hinterland were fortified to create a second line of defence. In addition, at vulnerable points, units of the Danube fleet were stationed. In the time of Emperor
Marcus Aurelius the first mention is made in Pannonia of stone watchtowers (
burgi, panelled towers and fortlets (
praesidia). In late antiquity, the Pannonian military district was divided into two parts (
pars inferior and
pars superior).) an expansionist policy in the
Black Sea area, conquering all regions from
Sinope to the mouths of the Danube. The young king then turned his attention to the
Anatolian peninsula, where Roman power, however, was steadily growing. He knew that a clash with Rome would prove fatal for one of the two sides. At the end of the
three Mithridatic Wars (89–63 BC), Rome prevailed and succeeded in annexing much of Anatolia, as far as
Syria and
Judaea. West of the Euphrates,
Augustus attempted to reorganize the Roman East, both by securing a non-aggression pact with the Parthian kingdom and obtaining the return of Crassus’ standards lost at Carrhae, and by incorporating some
client states into
Roman provinces, such as the
Galatia of
Amyntas in 25 BC, as well as strengthening old alliances with local rulers who became "
client kings of Rome", as happened with
Archelaus of
Cappadocia,
Asander of the
Bosporan Kingdom, and
Polemon I of the
Kingdom of Pontus, in addition to the rulers of
Iberia,
Colchis and
Albania. The eastern situation was destabilized by the deaths of the king of
Cappadocia Archelaus, who had come to Rome to pay homage to the new
princeps,
Tiberius, as well as
Antiochus III, king of
Commagene, and
Philopator, king of
Cilicia. The difficult eastern situation thus required a new Roman intervention, and in 18 Tiberius sent his adopted son
Germanicus who, with Parthian consent, crowned at
Artaxata the young
Zeno, son of
Polemon I and strongly pro-Roman, as king of Armenia. He also established that Cappadocia should be constituted as its own
province, and that Cilicia should instead be incorporated into the province of Syria. Following the annexation of Cappadocia under Tiberius (17/18), a number of
military forts were placed along the Euphrates to guard the northern sector of the eastern frontier. ,
Armenia,
Osroene and the
Parthian Empire around 50. After the death of Tiberius in 37, the Parthians forced Armenia to submit, although it appears that in 47 the Romans regained control of the kingdom and granted it the status of
client state. The situation remained fluid.
Nero, concerned that the Parthian king
Vologases I had placed his brother
Tiridates on the Armenian throne, decided to send his capable general
Gnaeus Domitius Corbulo in command of eastern operations. Corbulo reached a final agreement with the "
King of Kings" in 63, restoring Roman prestige and concluding with Tiridates an arrangement that recognized Armenia as a
Roman protectorate, which remained largely unchanged until the reign of
Trajan. The region was soon shaken by the outbreak of the
First Jewish–Roman War and the almost simultaneous
Roman civil war of 68–69, which brought a new reorganization of the entire
eastern frontier, so that two legions,
Legio XII Fulminata and
Legio XVI Flavia Firma, were assigned to
Cappadocia from 72/73.
East of the Euphrates: Mesopotamia and Osroene Between 224 and 226/227 an important event occurred that changed the course of relations between the
Roman Empire and the
Sasanian Empire: in the East the last Parthian ruler
Artabanus IV was overthrown after being defeated in "three battles" and the rebel
Ardashir I founded the
Sasanian dynasty, destined to be Rome's eastern adversary until the 7th century. After the death of Valerian, although the Roman Empire was under constant pressure from the
Germanic-Sarmatian invasions along the northern frontier, it was forced to react to the terrible defeat of 260, which had led to the subsequent
occupation of Antioch, the third largest Roman city after
Rome and
Alexandria. From this moment onward, for the following forty years, Roman armies advanced on at least three occasions deep into Sasanian territory, capturing their capital
Ctesiphon each time: first under
Odaenathus (
rector totius Orientis), then under the emperors
Carus and
Numerian, and finally under
Galerius under the supervision of
Diocletian. At the end of these campaigns, Mesopotamia returned under Roman control, Armenia was recognized as a Roman protectorate, and at
Nisibis the caravan routes of trade with the Far East (
China and
India) were concentrated. With the control of certain territories east of the
Tigris, the empire reached its greatest eastern expansion (298). The entire eastern frontier system was therefore strengthened, beginning with the construction of the
Strata Diocletiana in Syria and new fortified positions throughout Mesopotamia and Osroene. The peace treaty between Diocletian and the Sasanian king
Narseh lasted almost forty years. The Sasanian defeat at the hands of Diocletian and Galerius (peace of 298) guaranteed the Roman Empire more than thirty years of relative peace (until 334), and northern Mesopotamia returned under Roman control. The frontier was in fact moved as far as the
Khabur and the northern
Tigris, passing through the
Sinjar Mountains. , with the territories acquired during the thirty years of campaigns (306–337).
Limes Arabicus and the Strata Diocletiana The
Limes Arabicus was the frontier of the Roman province of
Arabia Petraea, facing the desert. It runs from the
Gulf of Aqaba in southern
Palestine to northern Syria, for about 1,500 kilometers (930 mi) at its greatest extent. The purpose of this defensive
limes was to protect the Roman province of
Arabia from attacks by the barbarian tribes of the Arabian desert. "For over five centuries the
Limes Arabicus protected the south-eastern frontier of the Roman Empire". Augustus' presence in the East immediately after the
Battle of Actium (30–29 BC) and again from 22 to 19 BC, as well as that of
Marcus Vipsanius Agrippa between 23–21 BC and again between 16–13 BC, demonstrated the importance of this strategic sector. It was necessary to reach a
modus vivendi with
Parthia, the only power capable of challenging Rome along the eastern frontiers. In practice both empires had more to lose from defeat than they could realistically gain from victory. Parthia therefore accepted that west of the Euphrates Rome would organize states as it pleased: Augustus thus incorporated some
client states into
Roman provinces (such as
Judaea of
Herod Archelaus in 6, after disturbances at the death of
Herod the Great in 4 BC) and strengthened older alliances with local rulers who now became "
client kings of Rome", as occurred with the rulers of
Emesa,
Iturea,
Commagene,
Cilicia and
Nabataea. at the beginning of the
5th century. While still preparing to conquer
Dacia,
Trajan arranged the annexation of
Arabia Petraea (105–106), and in the following years ordered the construction of an important frontier military road: the
Via Traiana Nova (between 111 and 114), which linked
Aelana on the
Red Sea with the
legionary fortress of
Bostra, 267 Roman miles away. Its primary purpose was to provide an efficient means for transporting troops and government officials. It was completed by
Hadrian. Its natural continuation from the end of the 3rd century would be the
Strata Diocletiana, which connected Bostra with the Euphrates. From 230 and for the following thirty years, Sasanian armies advanced into
Roman Mesopotamia, besieging numerous Roman garrisons along the Euphrates, and even conquering Mesopotamia and invading
Syria, including its capital
Antioch. There was a Roman
castrum every one hundred kilometres, with the aim of creating a line of protection and control. The troops were gradually withdrawn from the
Limes Arabicus in the first half of the 6th century and replaced by native Arab
foederati, particularly the
Ghassanids.
Southern frontier (Africa) (the frontier of Roman Africa (dark tan) in the late 2nd century AD: Septimius Severus expanded the Limes Tripolitanus dramatically (medium tan), even briefly holding a military presence (light tan) in the
Garamantian capital Garama in 203) Of the three land frontiers of the
Roman Empire, the
southern one was the longest. From
Rabat in
Morocco to
Suez on the
Red Sea in
Egypt it measured about 4,000 km as the crow flies. But the Roman frontier actually ran about a thousand kilometres south of
Cairo, and its course from there to the
Atlantic Ocean was far from straight. At the greatest extent of the Roman Empire, the southern border lay along the deserts of Arabia in the Middle East (see
History of the Romans in Arabia) and the Sahara in
North Africa, which represented a natural barrier against expansion. The Empire controlled the Mediterranean shores and the mountain ranges further inland. The Romans attempted twice to occupy the
Siwa Oasis and finally used Siwa as a place of banishment. However Romans controlled the
Nile many miles into Africa up to the modern border between Egypt and Sudan. In Africa Romans controlled the area north of the Sahara, from the Atlantic Ocean to Egypt, with many sections of limes (
Limes Tripolitanus, Limes Numidiae, etc.). The
Fossatum Africae ("African ditch") of at least 750 km controlled the southern borders of the Empire and had many similarities of construction to
Hadrian's Wall. There are similar, but shorter,
fossatae in other parts of North Africa. Between the Matmata and Tabaga ranges in modern
Tunisia there is a
fossatum which was duplicated during World War II. There also appears to be a 20 km
fossatum at
Bou Regreg, in
Morocco, although this would not have been within the scope of the proclamation of the
Codex Theodosianus because at that time the province was not in Africa, administratively speaking. In the south of
Mauritania Tingitana the frontier in the third century lay just north of
Casablanca near Sala and stretched to
Volubilis.
Septimius Severus expanded the "Limes Tripolitanus" dramatically, even briefly holding a military presence in the Garamantian capital Garama in 203 AD. Much of the initial campaigning success was achieved by
Quintus Anicius Faustus, the legate of
Legio III Augusta. Following his African conquests, the Roman Empire may have reached its greatest extent during the reign of
Septimius Severus, under whom the empire encompassed an area of 2 million square miles and the
Mauretanias. From the time of
Trajan, the borders of
Africa Proconsularis expanded southwards and westwards, occupying territories formerly belonging to the
Kings of Numidia, up to the highlands of the
Aures Mountains. Two fortified lines were established, one north and one south of the Aurès mountains, guarded by numerous forts and fortlets (in addition to the
legionary fortress of
Lambaesis) and integrated by a continuous
Fossatum Africae with outposts extending into the desert. (lighter brown). There was also, briefly, a Roman military presence in the Garamantian capital
Garama in 203. As for the
Limes Tripolitanus, it was the last section of the
limes Africanus to be organized, again thanks to Septimius Severus, who brought the
Roman Empire to its greatest expansion in North Africa and paid particular attention to this frontier sector. A similar development occurred in the
Mauretanian frontier sector, also under Septimius Severus, when a further southward advance in Caesariensis was accompanied by the construction of a new military road with forts, fortlets and watchtowers. A zone thus formed between the two roads (that of Trajan and Hadrian, and this later one of Septimius Severus), called
Nova Praetentura, where a form of defence in depth was implemented, whose territories served as a buffer zone for nomadic or semi-nomadic populations to the south. With the rise of
Diocletian, the empire underwent a radical internal transformation, especially at the military level. Divided into four parts (two
Augusti and two
Caesares), it was further divided into 12
dioceses, each entrusted to a
vicarius, subordinate to one of the four
Praetorian prefects. The vicarius in turn supervised all the provincial governors (variously titled
proconsules,
consulares,
correctores,
praesides). The troops stationed in each diocese were placed under a
comes rei militaris, dependent directly on the
magister militum and commanding the
duxes responsible for military command in individual provinces. At the end of 297 the
Augustus Maximian campaigned in
Mauretania, defeating the tribe known as the
Quinquegentiani, who had also penetrated
Numidia. The following year (298) he reinforced the African frontier from the Mauretanias to
Africa Proconsularis.
Fossatum Africae Fossatum Africae ("African ditch") is a linear defensive structure (
limes) that extended over 750 km or more in
northern Africa constructed during the
Roman Empire to defend and control the southern borders of the Empire in the
Roman province of Africa. It is considered to have many similarities of construction to
Hadrian's Wall at the northern border of the Empire in Britain. Generally the Fossatum consists of a ditch and earth embankments on either side using the material from the ditch. Sometimes the embankments are supplemented by dry stone walls on one or both sides; rarely, there are stone walls without a ditch. The width of the Fossatum is generally 3–6 m but in exceptional cases may be as much as 20 m. Wherever possible, it or its highest wall is constructed on the
counterscarp. Excavations near
Gemellae showed the depth there to be 2–3 m, with a width of 1 m at the bottom widening to 2–3 m at the top. The Fossatum is accompanied by many small watchtowers and numerous forts, often built within sight of one another.
Eastern African limes . The defence of the eastern African region mainly concerned the valley of the
Nile (a narrow strip of fertile land within surrounding desert, crucial for the
grain supply of
Rome), the
Mediterranean coasts from
Egypt to
Cyrenaica, certain landing points on the
Red Sea (such as
Berenice Troglodytica), important for trade with the Far East (from which spices and luxury goods were imported) and with the
Kingdom of Aksum, and finally the mountainous area of the
Eastern Desert, rich in mines of gold, emeralds, granite and porphyry. In 96 BC
Ptolemy Apion of the
Ptolemaic dynasty became the last Hellenistic ruler of
Cyrenaica. At his death he bequeathed his kingdom to the
Roman Republic. The new territories were organized into a
Roman province only in 74 BC with the arrival of the first
legatus pro praetore, assisted by a
quaestor. It consisted of five cities of Greek origin forming the so-called
Cyrenaican Pentapolis. After the
Battle of Philippi the region was assigned to
Mark Antony, who in 36 BC granted it to
Cleopatra Selene II, daughter of
Cleopatra VII; this situation lasted until the
Battle of Actium. Once victorious,
Octavian became the undisputed master of
Rome. He established the
province of Egypt in 30 BC. Egypt thus became an imperial province. A few years later (27 BC), within the reform of provincial administration, Augustus united
Crete and Cyrene into a single
senatorial province, governed by a proconsul of praetorian rank, with capital at
Gortyn on
Crete. These events were followed by numerous pacification campaigns along the eastern African frontier, through which many populations were fought and incorporated into the
Roman Empire between 29 BC and AD 1, as also recorded in the
Fasti triumphales. There was later a gradual reduction in the number of legions stationed in the area (from three to only one), which should not be misleading: the decrease in legionary forces corresponded to an increase in auxiliary forces. While there were few external dangers, the internal situation instead saw a progressive increase in social tensions, from banditry in the countryside to open revolts, such as the Jewish uprising of 115–117 or the revolt of the
Bucoli in 172, during the reign of
Marcus Aurelius, caused by excessive taxation. Under Diocletian, in 290 the
Saracens are mentioned for the first time, an Arab tribe settled in the
Sinai Peninsula that had attempted to invade
Syria. At the end of 297 the Augustus
Maximian defeated the
Quinquegentiani in Mauretania and in 298 strengthened the African frontier from the Mauretanias to
Africa Proconsularis. ==Post-Roman
limites==