
Map of Upper Germanic & Rhaetian Limes
The '''Limes Germanicus''' (Latin for ''Germanic frontier'') was a remarkable line of frontier (''
limes'') forts that bounded the ancient Roman provinces of
Germania Superior and
Raetia, and divided the
Roman Empire and the unsubdued
Germanic tribes, from the years 83 to 260. At its height, the limes stretched from near
Bonn on the
Rhine to near
Regensburg on the
Danube.
The Limes Germanicus was divided into:
★ The 'Lower'' (Northern) ''Germanic Limes', which extended from the
North Sea at
Katwijk in the
Netherlands along the
Rhine;
★ The 'Upper Germanic Limes' (also called simply "the Limes") started from the Rhine at
Rheinbröhl (
Neuwied (district)) across the
Taunus mountains to the river
Main (East of
Hanau), then along the Main to
Miltenberg, and from
Osterburken (
Neckar-Odenwald-Kreis) south to
Lorch (
Ostalbkreis) in a nearly perfect straight line of more than 70 km;
★ The proper 'Rhaetian Limes' extended east from Lorch to
Eining (close to
Kelheim) on the
Danube. The total length was 568 km (341 miles). It included at least 60 castles and 900 watchtowers.
History

Reconstructed Limes near Saalburg, Germany.
Roman border defences have become much better known through systematic excavations financed by Germany and through other research connected to them. In
2005, the remnants of the 'Upper Germanic & Rhaetian Limes' were inscribed on the
List of
UNESCO World Heritage Sites as ''
Frontiers of the Roman Empire.'' The
Saalburg is a reconstructed fortification and museum of the Limes near
Frankfurt.
Augustus
The first emperor who began to build fortifications along the border was
Augustus, shortly after the devastating Roman defeat in the
Battle of the Teutoburg Forest in
9 AD. Originally there were numerous Limes walls, which were then connected to form the 'Upper Germanic Limes' along the Rhine and the 'Rhaetian Limes' along the Danube. Later these two walls were linked to form a common borderline.
14 to c. 73
From the death of
Augustus (14 AD) until after 70 AD,
Rome accepted as her Germanic frontier the water-boundary of the
Rhine and upper
Danube. Beyond these rivers she held only the fertile plain of
Frankfurt, opposite the Roman border fortress of Moguntiacum (
Mainz), the southernmost slopes of the
Black Forest and a few scattered bridge-heads. The northern section of this frontier, where the Rhine is deep and broad, remained the Roman boundary until the empire fell. The southern part was different. The upper Rhine and upper Danube are easily crossed. The frontier which they form is inconveniently long, enclosing an acute-angled wedge of foreign territory between the modern
Baden and
Württemberg. The Germanic populations of these lands seem in Roman times to have been scanty, and Roman subjects from the modern
Alsace-Lorraine had drifted across the river eastwards. The motives alike of geographical convenience and of the advantages to be gained by recognising these movements of Roman subjects combined to urge a forward policy at Rome, and when the vigorous
Vespasian had succeeded
Nero, a series of advances began which gradually closed up the acute angle, or at least rendered it obtuse.

Remains of the Limes
Flavian dynasty
The first advance came about 74 AD, when what is now Baden was invaded and in part annexed and a road carried from the Roman base on the upper Rhine,
Strassburg, to the Danube just above
Ulm. The point of the angle was broken off.
The second advance was made by
Domitian about 83 AD. He pushed out from Moguntiacum, extended the Roman territory east of it and enclosed the whole within a systematically delimited and defended frontier with numerous blockhouses along it and larger forts in the rear. Among the blockhouses was one which by various enlargements and refoundations grew into the well-known
Saalburg fort on the
Taunus near
Bad Homburg. This advance necessitated a third movement, the construction of a frontier connecting the annexations of AD 74 and AD 83 . We know the line of this frontier which ran from the Main across the upland
Odenwald to the upper waters of the
Neckar and was defended by a chain of forts. We do not, however, know its date, save that, if not Domitian's work, it was carried out soon after his death, and the whole frontier thus constituted was reorganised, probably by
Hadrian, with a continuous wooden
palisade reaching from Rhine to Danube.
Hadrian and the Antonines
The angle between the rivers was now almost full. But there remained further advance and further fortification. Either Hadrian or, more probably, his successor
Antoninus Pius pushed out from the Odenwald and the Danube, and marked out a new frontier roughly parallel to, but in advance of these two lines, though sometimes, as on the Taunus, coinciding with the older line. This is the frontier which is now visible and visited by the curious. It consists, as we see it today, of two distinct frontier works, one, known as the Pfahlgraben, is an earthen mound with stakes on top and ditch in front of the mound, best seen in the neighbourhood of the Saalburg but once extending from the Rhine southwards into southern Germany. The other, which begins where the earthwork stops, is a wall, though not a very formidable wall, of stone, the Teufelsmauer; it runs roughly east and west parallel to the Danube, which it finally joins at
Heinheim near
Regensburg. The southern part of the Pfahlgraben is remarkably straight; for over 50 km it points almost absolutely true for
Polaris.

Tower of the Limes
It is a clear case of an ancient frontier laid out in American fashion. This frontier remained for about 100 years, and no doubt in that long period much was done to it to which precise dates are difficult to fix. It cannot even be absolutely certain when the frontier laid out by Pius was equipped with the manpitts and other special fortifications. But we know that the pressure of the barbarians began to be felt seriously in the later part of the
2nd century, and after long struggles the whole or almost the whole district east of the Rhine and north of the Danube was lost, seemingly all within one short period, about 250.
Late Roman empire
Germanic invasions in the late
3rd century led to the abandonment of the so-called "Upper Raetian Limes" in favour of a Roman defence line along the rivers
Rhine,
Iller and
Danube (Donau-Iller-Rhine-Limes) with watch towers in sight contact and heavily fortified castra at important passes (e.g. Castrum Rauracense instead of the previously unwalled
Augusta Raurica near to
Basel) and in the hinterland of the frontier (e.g.
Vindonissa in today's Switzerland).
Description and functionality of the limes
The limes itself is a very simple construction. It is similar to the fortification that a travelling troop of Roman soldiers would construct every evening, to protect the camp from attacks. On the outside, the soldiers dug a ditch. The earth from the ditch was used to build a mound. On top of the mound stakes were attached. The Limes had a deeper ditch and a higher mound. The stakes were higher too and on several parts of the limes, instead of stakes there was a simple wall.
Behind the wall/mound a system of control towers, built of wood or stone, was installed, each within sight of the next one, and usually able also to signal to the forts several kilometers to the rear.

The
Saalburg, a reconstruction of a Roman fort.
The limes was never able to prevent whole Germanic tribes from entering the territory of the Roman empire. This was not the intention of the builders. Near the watch towers, the limes was open to passage, especially by traders or persons coming to live or work within the empire. The purpose of the limes was control of the traffic. To cross the limes it was necessary to pass the towers, and so come to the notice of the garrison, or to climb or destroy the wall or the stakes. Only individuals or small groups could climb the obstacles without being noticed, and they could not drive stolen livestock with them. Large groups would be noticed. They could destroy one or several towers, but this also would come to the attention of the Romans. This knowledge of all groups crossing the border was important for the Roman empire. For a territory as large as the Roman empire, there were amazingly few soldiers. Almost all of the legions were based close to the frontiers. Any hostile group, who managed to pass this area of defense, could travel within the empire without significant resistance. The purpose of the limes was early warning of attack, deterrence of casual small-scale raiding, and the ability to react while the enemy was near the legions.
Towns and cities along the limes
Germany:
★
Rheinbrohl -
Bad Ems -
Miltenberg -
Lorch -
Weißenburg -
Eining
Lower Germanic Limes:
Germany
★
Xanten
The Netherlands
★
Nijmegen
★
Herwen-De Bijland
★
Arnhem-Meinerswijk
★
Maurik
★
Vechten
★
Utrecht
★
Woerden
★
Zwammerdam
★
Alphen aan den Rijn
★
Leiden-Roomburg
★
Valkenburg
★
Katwijk
Notes
References
Primary sources
(none yet)
Secondary sources
★
★ A good English account can be found in H. F. Pelham's essay in ''Trans. of the Royal Hist. Soc.'' vol. 20, reprinted in his ''Collected Papers'', pp. 178-211 (Oxford, 1910), where the German authorities are fully cited.
★ D.I. Woolliscroft, Roman Military Signalling. Stroud and Charleston: Tempus Publishing, 2001. Pp. 191. ISBN 0-7524-1938-2. A study mainly of intervisibility along the Rhine and British limites.
External links
★
The Upper German-Raetian border wall
See also