Construction of Hadrian’s Wall began in 122 C.E., and was the result of Hadrian’s overall goal of consolidating the Roman Empire and maintaining its existing borders. Although the situation in Britain leading up to the wall’s construction is not completely known, coin evidence indicates that there may have been a major victory over a British uprising in the year 119 C.E. If there was in fact an uprising at this time, it was simply one of many since Rome had expanded its empire onto the island. With this in mind, Hadrian’s Wall served multiple purposes as both a defensive structure and a controlled, permeable border designed to enhance Roman control of the territory. The numerous lines of defenses that make up the system which Hadrian’s Wall was the centerpiece of indicates that it was in fact designed to hinder an enemy attack, however it also allowed contact between the Roman South and Pictish North. Each milecastle along the length of Hadrian’s Wall had a gate, which made travel between the two halves of the island relatively easy. Had the Wall’s only purpose been defense, far fewer gates would have been included, as they are obvious weak points in the grand scheme of the defensive network. These gates were also unnecessary for troop movement, as the numerous infantry and cavalry forts along the wall were equipped with their own gates to allow Roman soldiers to patrol North and South of the wall. Thus, it can be concluded that the inclusion of almost 80 milecastle gates was done to allow non-military contact between the North and South, hence why Hadrian’s Wall can be thought of not only as a defensive structure but also as a controlled border crossing.
The decision to allow this contact also reflects the larger strategies of Roman control over their empire, as the Romanization of conquered peoples was a cornerstone of their administration. By allowing conquered peoples to enjoy the Roman lifestyle and identify as Romans, loyalty to the Empire was promoted, reducing the risk of insurrection. Although some populations still revolted against Roman rule, like the Picts and the Hebrews, many conquered peoples became so thoroughly Romanized that they regarded outsiders as barbarians, despite they themselves having been called barbarians previous to Roman rule.
The Wall in the North is a very different story, as its primary purpose is to permanently separate the people of the Seven Kingdoms from everyone North of the Wall. This is why, unlike Hadrian’s Wall, the Wall in the North has few routes through or around it, and the gates which do exist are used only by rangers going North. Instead of integrating the Wildlings into Westerosi culture, the peoples of the Seven Kingdoms have fought them for thousands of years in order to keep them out. The design of the Wall reflects this long struggle, as it is equipped with numerous missile weapons like catapults, torsion trebuchets and ballistae atop its icy parapet. This formidable arsenal atop the Wall makes it one of the strongest fortifications in all of Westeros, and is nearly impossible to overcome.
 David J. Breeze and Brian Dobson, Hadrian’s Wall (London: Penguin Books Ltd., 1977), 28.
 Patricia Southern, Roman Britain: A New History 55 BC-AD 450 (Gloucestershire: Amberly Publishing, 2011), 181.
 C.R. Whittaker, Rome and its Frontiers: The Dynamics of Empire (New York:Routledge, 2004), 34.
 H.H. Scullard, Roman Britain: Outpost of the Empire (London: Thames and Hudson Ltd., 1979), 37.