The limes was the Roman frontier system represented by Hadrian’s Wall and the Germanic-Raetian Limes.
In modern historical writing, limes refers to Rome’s defended and administered borders. These frontiers could include walls, ditches, forts, roads, watchtowers, rivers, and controlled crossing points. They were not always intended to form an impenetrable barrier.
Hadrian’s Wall marked part of the northern frontier of Roman Britain, while the Upper Germanic-Raetian Limes crossed parts of modern Germany. Other frontier zones followed major rivers, including the Rhine and Danube.
The Latin word limes originally had meanings connected with a boundary, path, or limit. Roman frontier policy varied by region and period, so the term does not describe one identical wall around the whole empire. It is better understood as a broad administrative and military concept.