Frontiers of the Roman Empire – The Danube Limes (Western Segment)

Brief synthesis

The Frontiers of the Roman Empire – The Danube Limes (Western Segment) ran for almost 600 km along the River Danube, following the northern and eastern boundaries of the Roman provinces of Raetia (eastern part), Noricum and the north of Pannonia, from Bad Gögging in Germany through Austria to Iža in Slovakia.

For more than 400 years from the 1st century CE, it constituted the middle European boundary of the Roman Empire against what were called ‘barbarians’.

First continuously defined in the Flavian dynasty (69-96 CE) and later further developed, the fortifications consisted of a continuous chain of military installations almost all along the southern banks of the river. The backbone of the defence system was a string of four legionary fortresses, each housing some 5,500 to 6,000 Roman citizens as soldiers. This number reflected Roman anxiety about powerful neighbours such as Germanic peoples in the north. Between the legionary fortresses, were forts, fortlets, and watchtowers linked by access roads and serviced by the Pannonian fleet that patrolled the River Danube under the control of Rome. To serve soldiers and civilians, sizeable civilian towns were developed around the legionary fortresses and some forts, and these towns also spread Roman culture to the edges of the Empire.

The form and disposition of the fortifications reflects the geomorphology of the river as well as military, economic and social requirements. For most of its length the western segment of the Danube frontier crosses wide floodplains, separated from each other by high mountain ranges that force the meandering river into deep, narrow gorges. These natural conditions are reflected in the size and positioning of military installations, with the gorges being secured by small, elevated posts, and the plains by larger forts at river crossings or other strategic points overlooking the plains. Although primarily for defence, in peaceful times the Limes also controlled trade and access across the river.

The western segment of the Danube Limes finally broke down in the 5th century CE. During the Middle Ages, many still standing Roman buildings were reused and served as nuclei for the development of villages and towns many of which exist today.

The 77 component parts, selected from a far larger number that still remain, together reflect in an outstanding way all elements of the well-balanced complex River Danube defensive system, linked by the military road parallel to the river. They also offer a clear understanding of the way Roman military strategies evolved over time to counter threats emanating from sustained large-scale migrations in the later years of the Roman Empire, particularly through the remains of a bridgehead fort and temporary camps on the left bank of the river.

The large number of civilian settlements present a vivid understanding of the lives of the military and civilians, and how defensive installations became the focus for trade and engagement with areas beyond the frontier, all of which brought about profound and long-lasting changes to the landscape of this part of Europe.

Criterion (ii): The legionary fortresses, forts, fortlets, watchtowers, linked infrastructure and civilian architecture that made up the Roman military system of the western segment of the Danube Limes extended technical knowledge of construction and management to the very edges of the Empire. This segment did not constitute an impregnable barrier but controlled and allowed the movement of peoples, not only military units, but also civilians and merchants. This triggered profound changes and developments in terms of settlement patterns, architecture and landscape design and spatial organisation in this part of the frontier which has persisted over time. The frontier landscape is thus an exceptional reflection of the imposition of a complex military system on existing societies in the northern part of the Empire.

Criterion (iii): The Frontiers of the Roman Empire – The Danube Limes (Western Segment) presents an exceptional manifestation of Roman imperial policy and the Empire’s ambition to dominate the world in order to establish its law and way of life in the long‐term. The segment reflects specifically how the Empire consolidated its northern frontiers at the maximum extension of its powers. It also witnesses Roman colonization through the spread of culture and different traditions – military engineering, architecture, art, religion, management and politics – from the capital to the remotest parts of the Empire. The large number of human settlements associated with the defences, contribute to an exceptional understanding of how soldiers and their families, and also civilians, lived in this part of the Empire, with all the accoutrements of Roman culture such as baths, religious shrines and, at the largest settlements like Carnuntum, amphitheatres and a governor’s palace.

Criterion (iv): The materials and substance of the Frontiers of the Roman Empire – The Danube Limes (Western Segment) can be seen as a vivid testimony to the way Roman military systems were influenced by geography and, over four centuries, were developed and adapted to meet changing threats to the Empire. Military campaigns are reflected by temporary camps built around existing forts, a bridgehead built on the left bank of the Danube River, and horseshoe and fanshaped towers and strongly fortified fortlets developed as a response in Late Roman times to changes in warfare. In Mediaeval times, many of the defensive constructions became the nuclei of later settlements and, through their continuous use until today, have shaped the form of medieval towns along the Danube.

Integrity

The series of component parts as a whole reflects all the key elements which once constituted the frontier system – that is the continuous chain of military installations along the southern banks of the river consisting of legionary fortresses, the backbone of the system, around which forts, fortlets, and watchtowers were laid out at varying distances – as well as the linking infrastructure and civilian settlements. The ensemble of component parts represents the long period in which the western segment of the Danube operated as part of the frontiers of the Roman Empire as well as all its main periods of construction from its establishment in the 1st century CE until its disintegration in the 5th century CE, and the extraordinary complexity and coherence of its frontier installations.

Although some individual component parts are fragmentary and have been affected by changes of land use, natural processes, and in some cases over-building, the visible remains and buried archaeological features are both sufficient in scope to convey their contribution to the overall series. The boundaries of all individual component parts encompass the relevant attributes necessary to support their contribution to Outstanding Universal Value. Later development overlaying parts of the frontier remains are treated as vertical buffer zones.

In a few component parts, integrity is impacted by infrastructural development and windfarms and these impacts need to be addressed, when opportunities arise, and further impacts prevented.

Authenticity

The western segment of the Danube Frontier clearly reflects the specificities of this part of the overall Roman Frontier through the way selection of sites has encompassed all the key elements from the legionary fortresses and their associated settlements to small forts and temporary camps, and the way they relate to topography. All the component parts have been subject to intensive study and research. Sources deployed include the full array of archaeological research techniques (past and present excavation, field survey, aerial photography, geophysics etc.) as well as archival evidence. The component parts have the capacity to clearly reflect their inherent value and their contribution to the Outstanding Universal Value. The one area where the value is less well articulated is in terms of the relationship of component parts to the River Danube, as the frontier and as a longitudinal transport artery for military support, goods and people. All the component parts originally had a dynamic relationship with the river. As the Danube in places has shifted its course considerably since Roman times, some components have lost this link. In places the original course has not been identified. This link needs strengthening on the basis of more research on the original course of the river.

Overall, the fabric of the upstanding remains is in a good state of conservation. Some of the underground components are very fragile and highly vulnerable to damage and erosion from continuing cultivation. Reconstruction has been undertaken at a number of component parts and in most cases, it is slight and historical. There is though little consistency of approach on how the difference between original and reconstructed fabric is revealed. The most extensive reconstruction is at Carnuntum, where work is still in progress and, although reversible, is in places conjectural. At Iža (Kelemantia), parts of the fort have been rebuilt in a way that is not readily distinguishable from original material.

There is a need for a clear and consistent approach to reconstruction across the whole series. Large-scale conjectural reconstruction on top of original fabric needs to be avoided. As much reconstruction work will require renewal as part of ongoing conservation programmes, there are opportunities for improvement. The landward side of some of the component parts has not always been protected adequately. At Carnuntum the close proximity of an extensive windfarm is visually intrusive.

Protection and management requirements

Each of the three participating States Parties has a discrete legal system and administrative processes for heritage protection at national, regional, and local levels, and in the federal states of Germany and Austria there are also discrete statutory frameworks for each federal component (the German component parts are confined to the Federal State of Bavaria). Although the detailed legal provisions and terminology for designation and protection vary in each State, the function and effect of the different national provisions is the same: they should ensure adequate long-term protection of the component parts and their setting, if both are appropriately defined, if landowners are cooperative and if the measures are effectively implemented by regional and local governments.

Within each State Party an appropriate management system has been developed, expressed through national Management Plans. The aim of these plans is to ensure that individual parts of the property are managed within an agreed overall framework of co-operation to achieve common standards of identification, recording, research, protection, conservation, management, and presentation in an interdisciplinary manner and within a sustainable framework. The plans will be regularly updated. The national management systems address also the interests and involvement of all stakeholders and the sustainable economic use of the property.

At the international level the participating States Parties have agreed a Joint Declaration for running and expanding the property. This sets out the terms of reference for an Intergovernmental Committee to coordinate at an international level the management and development of the whole World Heritage property and to work to common aims and objectives and a Danube Limes Management Group to provide the primary mechanism for sharing best practice for those directly responsible for site management.

On a supra-national level, the Frontiers of the Roman Empire – The Danube Limes (Western Segment) aims to cooperate intensively with the existing Frontiers of the Roman Empire properties, to create a cluster. The existing Bratislava Group, an international advisory body for the Frontiers as a whole, will also provide a supportive technical network.