ABSTRACT
While the walled edges of cities, citadels and castles are central elements in the history of defensive and urban design, so too are edges that stretch across the hinterlands, designed to protect empires and cultures. Examples include the Great Wall of China, Hadrian’s Wall, the Wall of Anthemius (or Theodosius) and, in the modern era, the Maginot Line and, of course, the Berlin Wall, which was more a containment vessel than a defensive structure. We focus on the first four examples as they illustrate the changing nature of large-scale defensive strategies, which tend to be cumulative over time by virtue of the massive investment required and which, like city design, are vulnerable to changing technology and to the adaptive strategies of attackers.
