Danube–Iller–Rhine Limes

The Danube–Iller–Rhine Limes (

Late Roman fortifications along the river Rhine (Rhenus) on the High Rhine (between Lake Constance and Basle) and on the Upper Rhine

(below Basle til Bingen) as well as the Upper Danube.

Location and function

The mainly

Alamannic raids, especially around the middle of the 3rd century AD, necessitated a new military security plan for the northwestern borders of the Roman Empire. The Upper German-Rhaetian Limes had never been thought of as a military defensive system and was therefore abandoned after 260 (the so-called Limesfall). The frontier troops were withdrawn to positions behind the more easily controlled rivers of the Rhine ("Rhenus"), Danube ("Danuvius") and Iller

("Hilaria"). Around 290, the systematic expansion of the new military border defences began.

The defensive facilities there, as illustrated by the large number of small fortresses, were not intended to ward off major attacks, but to ensure an almost unobstructed surveillance of the limes and deter plundering. Up to 378, the Romans invariably invaded the settlements of the Germani living beyond the limes (for example, under the emperors

Julian Apostata or Gratian

) to punish the tribes living there and intimidate them so that they refrained from attacks on the Empire. So late-Roman frontier defence was based, on the one hand, on the fortified belt of the Danube–Iller–Rhine Limes and, on the other hand, on offensive operations and preventive strikes in the tribal areas, as well as on alliances with Germanic princes. When around 400, these punitive expeditions were discontinued, the security situation deteriorated rapidly.

Gallery

Notitia Dignitatum: the forts under the command of the Dux Raetiae
Painting of Castrum Olinone as a symbol of the responsibility of the Comes for the section of the Rhine Limes in the Province of Maxima Sequanorum
Notitia Dignitatum: painting of Castrum Argentoratum as a symbol of the responsibility of the Comes for the section of the Rhine Limes in the region around Argentorate
Notitia Dignitatum: the castra and fortified towns under the command of the Dux Mogontiacensis
Remains of a Roman fighting tower in Constance (as at 2004)
Enceinte of the road fort of Irgenhausen (CH)
Artist’s impression of the road fort of Schaan (LI)
Ditch plan at Eining Roman Fort (D) with late antiquity reduction in the northwest corner of the castrum
Reconstructed foundation walls of the fort of Caelius Mons (Kellmünz/D)
Preserved foundations of a late Roman horseshow tower in Arbon (CH)