ABSTRACT
Through antiquity and into the Middle Ages, cities were defined by their walls. These barriers encased the city and set its outer boundaries. Settlements outside the walls were known as faubourgs. As the city grew outward, old walls were taken down and replaced by new ones to encompass the faubourgs, which by this time were joined to the city. And so it went; like a tree sprouting new layers of outward growth with each new age, additional settlements were incorporated into the city and walls laid out their contours.
