The Wetterau Limes is the name given in the field of historical research to that part of the Upper Germanic-Rhaetian Limes which enclosed the region that became known as the Wetterau in the German state of Hesse. During the two campaigns of the Roman Emperor Domitian against the Chatti, the Romans began to cut swathes of open ground through the dense forests of today's Hesse, in order to prevent their columns from being ambushed. On the crest of the Taunus mountain range, such a swathe served as a surveillance route. After the end of the Chatti Wars, the Romans began to secure these conquered regions east of the Rhine with a limes - a line of forts, fortlets and palisades; the forest road was guarded by wooden watchtowers to ensure continuous observation. This ensured that the southern slopes of the Taunus mountains and the fertile and strategically important Wetterau became part of the Roman Empire. In addition to the establishment of this frontier, Domitian turned the two Germanic military territories of Upper and Lower Germanian into Roman provinces.
In spite of this rather modest conquest, he was subsequently celebrated in Rome with great pomp as a triumphator and coins were minted with the ambitious claim Germania capta. The propaganda nature of this policy is evinced by the fact that in the narrow province of Upper Germania there were hardly any Germanii, the area was populated entirely by Celts; the long-held conviction that the Neckar-Odenwald Limes was erected at the same time as the Wetterau Limes after the Chatti wars, is now regarded as having been rejected. Although there were Roman military outposts on the eastern side of the Rhine from the seventies, the border running along the Odenwald-Neckar Line to Donnstetten is now dated by most sources as having not been erected before 98 AD; the state of preservation of the limes is poor due to the heavy agricultural use of the Wetterau. Only a few sections on the foothills of the Taunus, at Echzell and east of Hanau are visible above ground. In the early days of limes research, this situation meant that the eastern Wetterau section remained undiscovered.
This was not disproved until the 1880s by excavations of the Hanauer Geschichtsverein under Albert Duncker and Georg Wolff. Like the other sections of the Upper German-Raetian Limes, the Wetterau Limes was reinforced and expanded. In the eastern Wetterau the dates when the individual forts were first built are not uniform, it is clear that there was a defensive line from Oberflorstadt via Heldenbergen and Hanau-Mittelbuchen to Hanau-Salisberg The forts on the line further east from Marköbel via Rückingen to Großkrotzenburg were not built until the time of Trajan. The neighbouring Taunus line was reinforced in the second half of the second century by the numerus forts of Holzhausen, Kleiner Feldberg and Kapersburg; the further expansion of the limes defences to the north of the Wetterau was in order to protect its fertile soils on the one hand and to meet the high demand for the supply of the troops stationed on the limes and legion camps in Mainz. Archaeobotanical studies have calculated that an annual requirement of 3,034 tons of grain and 10,371 tons of hay were required to supply for the north-facing bulge of the limes in the Wetterau.
The end of the Wetterau Limes came in the year 259-260 AD, when Rome abandoned all areas to the east of the Rhine. Thus, for example, the pottery trade, once flourishing in the Wetterau came to a standstill. Imports of pottery from the Rhineland dominate archaeological collections from the second third of the 3rd century. Bricks found in the area do not seem to have been fired as they used to be. More and more older building material was used instead. Hypocaust heating was replaced by much simpler heating pipe systems. From the border area, there are other interesting finds which shed further light on the period of the limes; this includes the treasure of Ober-Florstadt, concealed during the course of Germanic invasions in AD 233. In 1603, the inscription of a collegium iuventutis was discovered in the area around Altenstadt Roman Fort; this may have been a unit set up to act as a local militia. Kapersburg Roman Fort was reduced during its last days. There is evidence of a local unit, a numberus nidensium, raised in the civitas capital of Nida-Heddernheim.
Lochmühle Fortlet Kapersburg Roman Fort Ockstädter Wald Fortlet Kaisergrube Fortlet Am Eichkopf Fortlet Langenhain Roman Fort Hunnenkirchhof Fortlet Butzbach Roman Fort Degerfeld Fortlet Dicker Wald Fortlet Holzheimer Unterwald Fortlet Hainhaus Fortlet Arnsburg Roman Fort Langsdorf Fortlet Feldheimer Wald Fortlet Inheiden Roman Fort Auf dem Wingertsberg Fortlet Massohl Fortlet Auf der Burg Fortlet Haselheck Fortlet Echzell Roman Fort Lochberg Fortlet Staden Fortlet Ober-Florstadt Roman Fort Stammheim Fortlet Altenstadt Roman Fort Auf dem Buchkopf Fortlet Marköbel Roman Fort Langendiebach Fortlet Rückingen Roman Fort Neuwirtshaus Fortlet Großkrotzenburg Roman Fort The following museums have a permanent exhibition on the Wetterau Limes or individual sites along it: Saalburg Museum, Bad Homburg Wetterau Museum, Friedberg Butzbach Municipal Museum Limes Information Centre at Hof Graß Echzell Local History Museum Heuson Museum, Büdingen Erlensee-Rückingen Local History Museum Schloss Steinheim Museum Großkrotzenburg Museum Limes Dietwulf Baatz and Fritz-Rudolf
Hadrian's Wall called the Roman Wall, Picts' Wall, or Vallum Hadriani in Latin, was a defensive fortification in the Roman province of Britannia, begun in AD 122 in the reign of the emperor Hadrian. It ran from the banks of the River Tyne near the North Sea to the Solway Firth on the Irish Sea, was the northern limit of the Roman Empire north of which were the lands of the northern Ancient Britons, including the Picts, it had a stone wall. There were milecastles with two turrets in between. There was a fort about every five Roman miles. From north to south, the wall comprised a ditch, military way and vallum, another ditch with adjoining mounds, it is thought the milecastles were staffed with static garrisons, whereas the forts had fighting garrisons of infantry and cavalry. In addition to the wall's defensive military role, its gates may have been customs posts. A significant portion of the wall still stands and can be followed on foot along the adjoining Hadrian's Wall Path; the largest Roman archaeological feature anywhere, it runs a total of 73 miles in northern England.
Regarded as a British cultural icon, Hadrian's Wall is one of Britain's major ancient tourist attractions. It was designated as a UNESCO World Heritage Site in 1987. In comparison, the Antonine wall, thought by some to be based on Hadrian's wall, was not declared a World Heritage site until 2008, it is a common misconception that Hadrian's Wall marks the boundary between Scotland. In fact Hadrian's Wall lies within England and has never formed the Anglo-Scottish border. While it is less than 0.6 mi south of the border with Scotland in the west at Bowness-on-Solway, in the east at Wallsend it is as much as 68 miles away. Hadrian's Wall was 117.5 km long. East of the River Irthing, the wall was made from squared stone and measured 3 metres wide and 5 to 6 metres high, while west of the river the wall was made from turf and measured 6 metres wide and 3.5 metres high. These dimensions do not include the wall's ditches and forts; the central section measured eight Roman feet wide on a 3 m base. Some parts of this section of the wall survive to a height of 3 m.
South of the wall, a large ditch was dug, with adjoining parallel mounds, one on either side. This is known today as the Vallum though the word vallum in Latin is the origin of the English word wall, does not refer to a ditch. In many places – for example Limestone Corner – the Vallum is better preserved than the wall, robbed of much of its stone. Hadrian's Wall extended west from Segedunum at Wallsend on the River Tyne, via Carlisle and Kirkandrews-on-Eden, to the shore of the Solway Firth, ending a short but unknown distance west of the village of Bowness-on-Solway; the A69 and B6318 roads follow the course of the wall from Newcastle upon Tyne to Carlisle along the northern coast of Cumbria. Although the curtain wall ends near Bowness-on-Solway, this does not mark the end of the line of defensive structures; the system of milecastles and turrets is known to have continued along the Cumbria coast as far as Risehow, south of Maryport. For classification purposes, the milecastles west of Bowness-on-Solway are referred to as Milefortlets.
Hadrian's Wall was planned before Hadrian's visit to Britain in 122. According to restored sandstone fragments found in Jarrow which date from 118 or 119, it was Hadrian's wish to keep "intact the empire", imposed on him via "divine instruction". Although Hadrian's biographer wrote " was the first to build a wall 80 miles long to separate the Romans from the barbarians", reasons for the construction of the wall vary, no recording of an exact explanation survives. Theories have been presented by historians of an expression of Roman power and Hadrian's policy of defence before expansion. On his accession to the throne in 117, there was unrest and rebellion in Roman Britain and from the peoples of various conquered lands across the Empire, including Egypt, Judea and Mauritania; these troubles may have influenced Hadrian's plan to construct the wall as well as his construction of limites in other areas of the Empire, but to what extent is unknown. Scholars disagree over how much of a threat the inhabitants of northern Britain presented and whether there was any economic advantage in defending and garrisoning a fixed line of defences like the Wall, rather than conquering and annexing what has become the Scottish Lowlands and defending the territory with a loose arrangement of forts.
The limites of Rome were never expected to stop tribes from migrating or armies from invading, while a frontier protected by a palisade or stone wall would help curb cattle-raiders and the incursions of other small groups, the economic viability of constructing and keeping guarded a wall 72 miles long along a sparsely populated border to stop small-scale raiding is dubious. Another possible explanation for the wall is the degree of control it would have provided over immigration and customs. Limites did not mark the boundaries of the empire: Roman power and influence extended beyond the walls. People within and beyond the limites travelled through it each day when conducting business, organised check-points like those offered by Hadrian's Wall provided good opportunities for taxation. With watch towers only a short distance from gateways in the limites, patrolling legionaries could have kept track of
The Main Limes called the Nasser Limes, was built around 90 A. D. and, as part of the Upper Germanic-Rhaetian Limes, formed the frontier of the Roman Empire in the area between the present day villages of Großkrotzenburg and Bürgstadt. In this section the limes adjoined the River Main, which forms a natural boundary for about 50 kilometres here, so "Main" refers to the river. In order to secure the riverbank, it was sufficient to erect free-standing towers backed up by the forts of the units stationed nearby. However, of the many watchtowers that stood along the Main, to date only one south of Obernburg am Main has been identified. On the other bank of the Main was the uninhabited Spessart, a wooded hill range which, like the Odenwald which borders it to the south-west, was interesting for the Romans because of its timber. In inscriptions, there are reports of the logging vexillationes of the 22nd Legion, which were stationed in Obernburg and Trennfurt. In the majority of forts, settlement activity continued after the fall of the limes, why, as in Obernburg Niedernberg and Großkrotzenburg, they are now located below the medieval village centres.
In Grosskrotzenburg, Hainstadt and Obernburg, Alamannic artefacts were discovered. North of the Main the limes runs through the marshy terrain of the Schifflache and Bulau before linking up with the Wetterau Limes. At the crossing of the Main at Großkrotzenburg a Roman bridge has been identified from post sockets. In the south it extended in its early period to Wörth; the exact start point of the Odenwald Limes has still not been identified. When the Odenwald Limes was abandoned in the 2nd century A. D. by Antoninus Pius and the establishment of the newer limes in the Bauland, the Main Limes was extended, because the forts in Trennfurt and Miltenberg were added. Because little remains of the forts, Roman artefacts are displayed in local museums such as Obernburg Romand Museum, Miltenberg Municipal Museum, Aschaffenburg Diocesan Museum and Großkrotzenburg Museum. Several fort sites such as Obernburg and Stockstadt have a rich collection of stone monuments. Dietwulf Baatz, Fritz-Rudolf Herrmann: Die Römer in Hessen.
Lizenzausgabe der 3rd edition, 1989, Hamburg, 2002, ISBN 3-933203-58-9. Bernhard Beckmann: Neuere Untersuchungen zum römischen Limeskastell Miltenberg-Altstadt. Verlag Michael Lassleben. Kallmünz, 2004, ISBN 3-7847-5085-0. Bernd Steidl: Welterbe Limes – Roms Grenze am Main. Begleitband zur Ausstellung in der Archäologischen Staatssammlung Munich, 2008. Logo, Obernburg, 2008, ISBN 3-939462-06-3. Kurt Stade: Die Mainlinie von Seligenstadt bis Miltenberg mit einem Nachtrage zur Abt. B Nr. 33 Kastell Stockstadt. In: Ernst Fabricius, Felix Hettner, Oscar von Sarwey: Der obergermanisch-raetische Limes des Roemerreiches. Abt. A, Strecke 6, pp. 3–70. Britta Rabold, Egon Schallmayer, Andreas Thiel: Der Limes. Die Deutsche Limes-Straße vom Rhein bis zur Donau. Verein Deutsche Limes-Straße, K. Theiss Verlag, Stuttgart, 2000, ISBN 3-8062-1461-1
Roman siege engines
Roman siege engines were, for the most part, adapted from Hellenistic siege technology. Small efforts were made to develop the technology. Up to the first century BC, the Romans utilized siege weapons only as required and relied for the most part on ladders and rams to assault a fortified town. Ballistae were employed, but held no permanent place within a legion's roster, until in the republic, were used sparingly. Julius Caesar took great interest in the integration of advanced siege engines, organizing their use for optimal battlefield efficiency. To facilitate this organization and the army’s self-sufficiency, an engineering corps was developed. An officer of engineers, or praefectus fabrum, is referenced in armies of the late republic, but this post is not verifiable in all accounts and may have been a military advisor on the personal staff of a commanding officer. There were legion architects who were responsible for the construction of war machines who would assure that all artillery constructions in the field were level.
Ensuring that constructions were level was the job of the libratores, who would launch missiles and other projectiles during battle. The engineering corps was in charge of massive production prefabricating artillery and siege equipment to facilitate its transportation. Roman artillery was efficient at that time, during a siege the Romans would attack the weakest area of their enemy's defenses and attempt to breach the walls at that point. To support this effort, artillery fire would commence, with three main objectives: to cause damage to defenses, casualties among the opposing army, loss of enemy morale, it would provide cover fire for troops building siege ramps or those in siege towers. There were machines called tormenta, which would launch projectiles such as javelins, rocks, or beams; these devices were on wheeled platforms to follow the line’s advance. All were "predicated on a principle of physics: a lever was inserted into a skein of twisted horsehair to increase torsion, when the arm was released, a considerable amount of energy was thus freed".
It was stated that sinew, instead of twisted hair, provided a better “spring.” These weapons were high-maintenance devices and vulnerable to having their leather, sinew, or hemp skeins affected by wet or damp, which would cause them to slacken and lose tension, rendering the engine useless. It is somewhat difficult to define and describe Roman artillery, as names are confused and historians still do not agree on all definitions. Best known are the ballista, the onager, the scorpio. After the absorption of the ancient Greek city states into the Roman Republic in 146 BC, some advanced Greek technologies began to spread across many areas of Roman influence; this included the hugely advantageous military advances the Greeks had made, as well as all the scientific, mathematical and artistic developments. The Romans'inherited' the torsion powered ballistae which had by now spread to several cities around the Mediterranean, all of which became Roman spoils of war in time, including one from Pergamum, depicted among a pile of'trophy' weapons in relief on a balustrade.
The torsion ballista, developed by Alexander, was a far more complicated weapon than its predecessor, the Romans developed it further. Vitruvius, in his De Architectura book X, describes the tuning of ballistae; every century in the Roman army had a ballista by the 1st century AD. It was the command of the chief of the ballistae, under whom were the artillery experts, or doctores ballistarum and the artillerymen, or ballistarii. Ballistae were heavy missile weapons, they resembled large crossbows, rather than catapults. They were powered by two horizontal like arms, which were inserted into two vertical and wound "skein" springs contained in a rectangular frame structure making up the head or principal part of the weapon; the arms were drawn rearward with a winch lever to further twist the skeins and thus gain the torsion power to cast a projectile. It has been said that the whirring sound of a ballista-fired stone struck fear and dread into the hearts of those inside the walls of besieged cities.
The stones chosen to be used in the ballista had to be a particular sort. According to Vegetius, river stones were best, since they are round and dense. Ballista stones found at the site of Masada were chiseled to make them as round as possible; the early Roman ballistae were made of wood, held together with iron plates around the frames and iron nails in the stand. The main stand had a slider on the top, into which were loaded the bolts or stone'shot'. Attached to this, at the back, was a pair of winches and a claw, used to ratchet the bowstring back to the armed firing position. A slider passed through the field frames of the weapon, in which were located the torsion springs, which were twisted around the bow arms, which in turn were attached to the bowstring. Drawing the bowstring back with the winches twisted the taut springs, storing the energy to fire the projectiles; the ballista was a accurate weapon, but some design aspects meant it could compromise its accuracy for range. The lightweight bolts could not gain the high momentum of the stones over the same distance as those th
The Pannonian Limes is that part of the old Roman fortified frontier known as the Danubian Limes that runs for 420 kilometres from the Roman camp of Klosterneuburg in the Vienna Basin in Austria to the castrum in Singidunum in present-day Serbia. The garrisons of these camps protected the Pannonian provinces against attacks from the north from the time of Augustus to the beginning of the 5th century. In places this section of the Roman limes crossed the river into the territory of the barbarians; the Danubian limes was one of the most turbulent regions in the European part of the Roman Empire and, during more than 400 years of Roman rule, Pannonia was one of its most important provinces after the abandonment of Dacia Traiana in 271 AD, because from that point on, the pressure of migrating peoples on this section of the limes increased still further. The limes had a great influence on the economic and cultural life of the civilian population because its hinterland was one of the main supply areas for the border troops and these in turn were the guarantors of the rapid Romanisation of the province.
The majority of the occupying forces were stationed in camps, small forts, watchtowers and fortified bridgeheads that were built at regular intervals along the riverbank. In an emergency, these units were reinforced by the legions which had their headquarters in four major military garrison towns. With its advance to the Danube, the Roman Empire became engaged in a long series of conflicts with trans-Danubian Germanic and Sarmatian barbarian and migrant peoples, that ended in the 5th century with the collapse of the Empire in the west. Roman camp or castrum Pannonia Danubian Limes Jenő Fitz: Der Römische Limes in Ungarn. Fejér Megyei Múzeumok Igazgatósága, 1976. Kurt Genser: Der österreichische Donaulimes in der Römerzeit. Ein Forschungsbericht. Verlag der Österreichischen Akademie der Wissenschaften, Vienna, 1986, ISBN 3-7001-0783-8. Kurt Genser: Der österreichische Limes in der Römerzeit. Ein Forschungsbericht Salzburg 1982, Teil II. Manfred Kandler, Hermann Vetters: Der römische Limes in Österreich, Vienna, 1989.
Sándor Soproni: Die letzten Jahrzehnte des pannonischen Limes. Becksche Verlagsbuchhandlung, Munich, 1985, ISBN 3-406-30453-2. Sándor Soproni: Der spätrömische Limes zwischen Esztergom und Szentendre. Akademiai Kiado, Budapest, 1978, ISBN 963-05-1307-2. Template:PECS Sándor Soproni: Militär und Befestigungen am Pannonischen Limes, ed. Amt der NÖ Landesregierung, Abt. III/2, Catalogue of the Lower Austrian State Museum, New Issue No. 55, Die Römer an der Donau, Noricum und Pannonien, Vienna, 1973, pp 59–68. Endre Tóth: Die spätrömische Militärarchitektur in Transdanubien. In Archaeologiai Értesitő. 134, Budapest 2009. Zsolt Visy: The Roman Army in Pannonia. An Archaeological Guide of the Ripa Pannonica. Teleki László Foundation, Budapest, 2003. ISBN 963-86388-2-6. Zsolt Visy: The ripa Pannonica in Hungary. Akadémiai Kiadó, Budapest, 2003, ISBN 963-05-7980-4. Zsolt Visy, Endre Tóth, Dénes Gabler, Lazlo Kocsis, Peter Kovacs, Zsolt Mráv, Mihaly Nagy u. a.: Von Augustus bis Attila – Leben am ungarischen Donaulimes.
Konrad Theiss Verlag, Stuttgart, 2000, ISBN 3-8062-1541-3. Zsolt Visy: Der pannonische Limes in Ungarn. Konrad Theiss Verlag, Stuttgart, 1988, ISBN 3-8062-0488-8. Herma Stiglitz: Militär und Befestigungen am Österreichischen Limes, ed. Office of the Lower Austrian State Government, Dept. III/2, Catalogue of the Lower Austrian State Museum, New Series No. 55, Die Römer an der Donau, Noricum und Pannonien, Vienna, 1973, pp. 45–59. Frantisek Krizek: Die römischen Stationen im Vorland des norisch-pannonischen Limes bis zu den Markomannenkriegen. In: Studien zu den Militärgrenzen Roms. Vorträge des 6. Internationalen Limeskongresses in Süddeutschland. Böhlau Verlag, Cologne/Graz, 1967, pp. 131–137. Miroslava Mirkovic: Orbis Provinciarum, Moesia Superior, Eine Provinz an der Mittleren Donau, Zaberns Bildbände zur Archäologie, Sonderbände der Antiken Welt, Verlag Philipp v. Zabern, Mainz, 2007, ISBN 978-3-8053-3782-3. Orsolya Heinrich-Tamáska: Überlegungen zu den Hauptgebäuden der pannonischen Innenbefestigungen im Kontext spätrömischer Villenarchitektur, pp. 233 - 242, in: Gerda v. Bülow und Heinrich Zahbelicky: Bruckneudorf und Gamzigrad.
Spätantike Paläste und Großvillen im Donau-Balkan. Raum, Files of the International Colloquium in Bruckneudorf from 15 to 18 October 2008, Dr. Rudolf Habelt GmbH, Bonn, 2011. ISBN 978-3-900305-59-8. Monuments Board of the Slovak Republic: Danube Limes in Slovakia. Ancient Roman Monuments on the Middle Danube. Printed Final Document to nominate the Slovakian Limes as a UNESCO World Heritage Site. Bratislava, 2011, pdf 5.76 MB, retrieved 4 May 2013 Zsolt Máté et al.: Frontiers of the Roman Empire. Ripa Pannonica in Hungary. Nomination statement Vol. 1. National Office of Cultural Heritage, Budapest, 2011, ISBN 978-963-7474-31-6, pdf 3.07 MB, retrieved 4 May 2013 Zsolt Máté et al.: Frontiers of the Roman Empire. Ripa Pannonica in Hungary. Nomination statement Vol. 2. Maps and plans, showing the boundaries of the buffer zone. National Office of Cultural Heritage, Budapest, 2011, pdf 119 MB, retrieved 4 May 2013 Zsolt Visy: The Danube Limes Project Archaeological Research Between 2008–2011. University of Pécs, Department of Archaeology, Pécs, 2011, ISBN 978-963-642-447-3, pdf 24 MB, retrieved 4 May 2013Carnuntum: Archäologischer Park CarnuntumAquincum: Artist’s impression of the Late Anquity East Gate of the LL Artist’s impression of the civilian town Artist’s impression of a residence Remains of the amphitheatreBinnenkastelle: Descript
The Saxon Shore was a military command of the late Roman Empire, consisting of a series of fortifications on both sides of the English Channel. It was established in the late 3rd century and was led by the "Count of the Saxon Shore". In the late 4th century, his functions were limited to Britain, while the fortifications in Gaul were established as separate commands. Several Saxon Shore forts survive in south-east England. During the latter half of the 3rd century, the Roman Empire faced a grave crisis. Internally, it was weakened by civil wars, the violent succession of brief emperors, secession in the provinces, while externally it faced a new wave of attacks by "barbarian" tribes. Most of Britain had been part of the empire since the mid-1st century, it was protected from raids in the north by the Hadrianic and Antonine Walls, while a fleet of some size was available. However, as the frontiers came under increasing external pressure, fortifications were built throughout the Empire in order to protect cities and guard strategically important locations.
It is in this context. In the 230s, under Severus Alexander, several units had been withdrawn from the northern frontier and garrisoned at locations in the south, had built new forts at Brancaster and Caister-on-Sea in Norfolk and Reculver in Kent. Dover was fortified in the early 2nd century, the other forts in this group were constructed in the period between the 270s and 290s; the only contemporary reference we possess that mentions the name "Saxon Shore" comes in the late 4th century Notitia Dignitatum, which lists its commander, the Comes Litoris Saxonici per Britanniam, gives the names of the sites under his command and their respective complements of military personnel. However, due to the absence of further evidence, theories have varied between scholars as to the exact meaning of the name, the nature and purpose of the chain of forts it refers to. Two interpretations were put forward as to the meaning of the adjective "Saxon": either a shore attacked by Saxons, or a shore settled by Saxons.
Some argue that the latter hypothesis, less valid, is supported by Eutropius, who states that during the 280s the sea along the coasts of Belgica and Armorica was "infested with Franks and Saxons", that this was why Carausius was first put in charge of the fleet there. However, Eutropius refers to Saxons as seaborne invaders, it receives at least partial support from archaeological finds, as artefacts of a Germanic style have been found in burials, while there is evidence of the presence of Saxons in some numbers in SE England and the northern coasts of Gaul around Boulogne-sur-Mer and Bayeux from the middle of the 5th century onwards. This, in turn, mirrors a well documented practice of deliberately settling Germanic tribes to strengthen Roman defences; the other interpretation, supported by Stephen Johnson, holds that the forts fulfilled a coastal defence role against seaborne invaders Saxons and Franks, acted as bases for the naval units operating against them. This view is reinforced by the parallel chain of fortifications across the Channel on the northern coasts of Gaul, which complemented the British forts, suggesting a unified defensive system.
Other scholars like John Cotterill however consider the threat posed by Germanic raiders, at least in the 3rd and early 4th centuries, to be exaggerated. They interpret the construction of the forts at Brancaster, Caister-on-Sea and Reculver in the early 3rd century and their location at the estuaries of navigable rivers as pointing to a different role: fortified points for transport and supply between Britain and Gaul, without any relation to countering seaborne piracy; this view is supported by contemporary references to the supplying of the army of Julian by Caesar with grain from Britain during his campaign in Gaul in 359, their use as secure landing places by Count Theodosius during the suppression of the Great Conspiracy a few years later. Another theory, proposed by D. A. White, was that the extended system of large stone forts was disproportionate to any threat by seaborne Germanic raiders, that it was conceived and constructed during the secession of Carausius and Allectus in 289-296, with an different enemy in mind: they were to guard against an attempt at reconquest by the Empire.
This view, although disputed, has found recent support from archaeological evidence at Pevensey, which dates the fort's construction to the early 290s. Whatever their original purpose, it is certain that in the late 4th century the forts and their garrisons were employed in operations against Frankish and Saxon pirates. Britain was abandoned by Rome with Armorica following soon after; the forts on both sides continued to be inhabited in the following centuries, in Britain in particular several continued in use well into the Anglo-Saxon period. The nine forts mentioned in the Notitia Dignitatum for Britain are listed here, from north to south, with their garrisons. Branodunum. One of the earliest forts, dated to the 230s, it is of a typical rectangular castrum layout. It was garrisoned by the Equites Dalmatae Brandodunenses, although evidence exists suggesting that its original garrison was the cohors I Aquitanorum. Gariannonum. Established between 260 and the mid-270s to guard the River Yare, it was garrisoned by the Equites Stablesiani Gariannoneses.
Although there is some discussion as to whet
Roman military engineering
The military engineering of Ancient Rome's armed forces was of a scale and frequency far beyond that of any of its contemporaries'. Indeed, military engineering was in many ways institutionally endemic in Roman military culture, as demonstrated by the fact that each Roman legionary had as part of his equipment a shovel, alongside his gladius and pila. Fabri were workers, craftsmen or artisans in Roman society and descriptions of early Roman army structure attributed to king Servius Tullius describe there being two centuriae of fabri under an officer, the praefectus fabrum. Roman military engineering took both routine and extraordinary forms, the former a proactive part of standard military procedure, the latter of an extraordinary or reactionary nature; each Roman legion had a military legionary fort as its permanent base. However, when on the march in enemy territory, the legion would, after a day's marching, construct a fortified camp or castra, requiring as raw materials only earth and timber.
Camp construction was the responsibility of special engineering units to which specialists of many types belonged, officered by architecti, from a class of troops known as immunes since they were excused from or immune from, regular duties. These engineers would requisition manual labor from the soldiers at large as required. A legion could throw up a camp under enemy attack in as little as a few hours. Judging from the names, they used a repertory of camp plans from a set textbook, selecting the one appropriate to the length of time a legion would spend in it: tertia castra, quarta castra: "a camp of three days", "four days", etc; the engineers built bridges from both timber and stone depending on required permanence, time available etc. Some Roman stone bridges survive to this day. Stone bridges were made possible by the innovative use of the keystone to allow an arch construction. One of the most notable examples of military bridge-building in the Roman Empire was Julius Caesar's Bridge over the Rhine River.
This bridge was completed in only ten days and is conservatively estimated to have been more than 100 m long. The construction was deliberately over-engineered for Caesar's stated purpose of impressing the Germanic tribes, who had little experience of engineering, to emphasise that Rome could travel wherever she wished. Caesar was able to cross over the completed bridge and explore the area uncontested, before crossing back over and dismantling the bridge. Caesar relates in his War in Gaul that he "sent messengers to the Sugambri to demand the surrender of those who had made war on me and on Gaul, they replied that the Rhine was the limit of Roman power"; the bridge was intended to show otherwise. Although most Roman siege engines were adaptations from earlier Greek designs, the Romans were adept at engineering them swiftly and efficiently, as well as innovating variations such as the repeating ballista; the 1st century BC army engineer Vitruvius describes in detail many of the Roman siege machines in his manuscript De Architectura.
When invading enemy territories, the Roman army would construct roads as they went, to allow swift reinforcement and resupply, as well as a path for easy retreat if necessary. Roman road-making skills are such. Michael Grant credits the Roman building of the Via Appia with winning them the Second Samnite War; the Roman army took part in building projects for civilian use. There were sound reasons for the use of the army in building projects: that if they weren't directly engaged in military campaigns, the legions were unproductive, costing the Roman state large sums of money, but the involvement of the soldiers in building works, kept them not only well accustomed to hard physical labour, but kept them busy, since it was the held belief that busy armies weren't plotting to mutiny, whereas idle armies were. Of both military and civilian use was the construction of roads within the boundaries of the Empire, in which the army was involved, but so too were soldiers put to use in the construction of town walls, the digging of shipping canals, the drainage of land, harbours in the cultivation of vineyards.
In some rare cases soldiers were used in mining work. They were skilled in conducting mining operations such as building the many aqueducts needed for prospecting for metal veins, in methods like hydraulic mining, the building of reservoirs to hold the water at the minehead, it is that they were capable of building and operating mine equipment such as water mills, stamp mills and dewatering machines. It is that they were involved in exploiting gold resources such as those at Dolaucothi in south west Wales, it was developed soon after conquest of the region under Frontinus, the local auxiliary troop came from north-west Spain, a country where gold mining developed on a large scale in the early part of the first century AD. The knowledge and experience learned through such routine engineering lent itself to any extraordinary engineering projects required by the army, it is here that the scale of Roman military engineering exceeded that of any of its contemporaries in both imagination and scope.
One of the most famous of such extraordinary constructions was the circumvallation of the entire city of Alesia and its Celtic leader Vercingetorix, within a massive length of double-wall – one inward-facing to prevent escape or offensive sallies from the city, one outward-facing to prevent attack by Celtic reinforcements. This wall is estimated to have been over 20 km long. A second example would be the massive ramp built using thousands of ton