Editing Fortification (section)

===Ancient Rome===
{{Main|Roman military frontiers and fortifications}}
[[File:Celio - le mura tra porta san Sebastiano e porta Ardeatina 2004.JPG|thumb|An interior view of the [[Aurelian walls]] near [[Porta San Sebastiano]]]]

The [[ancient Rome|Romans]] fortified their cities with massive, mortar-bound stone walls. The most famous of these are the largely extant [[Aurelian Walls]] of [[Rome]] and the [[Theodosian Walls]] of [[Constantinople]], together with partial remains elsewhere. These are mostly city gates, like the [[Porta Nigra]] in [[Trier]] or [[Newport Arch]] in [[Lincoln, Lincolnshire|Lincoln]]. 

[[Hadrian's Wall]] was built by the [[Roman Empire]] across the width of what is now [[northern England]] following a visit by [[List of Roman Emperors|Roman Emperor]] [[Hadrian]] (AD&nbsp;76–138) in AD&nbsp;122.