Hadrian’s Wall was garrisoned almost exclusively by auxiliary units. These men were either light infantry armed with spears, shields and missile weapons, or cavalry. Unlike their Legionary counterparts, these soldiers typically fought in more individualistic roles instead of a phalanx. While stationed at Hadrian’s Wall, these troops would have acted as sentries, and were the first line of defense against an enemy attack. These men were stationed in the numerous milecastles along the wall, typically in groups of sixty men per milecastle. The seventeen forts along the wall also housed additional units, with each fort typically housing around one-thousand soldiers. However the soldiers in the forts were not auxiliaries, but were instead Roman Legionaries, the best soldiers the Empire had to offer. These men were heavy infantry clad in lorica segmentata and chainmail armour, and carried pilum javelins and short stabbing swords. These soldiers were intended to repel an enemy attack which could not be held off by the auxiliaries on the wall, and would most likely have been deployed along the Vallum running parallel to the curtain wall. In addition to defending the fortifications, the Legionaries stationed along Hadrian’s Wall also carried out patrols North of the wall, and engaged in punitive attacks against tribes that challenged the Roman garrison.
The Wall in Westeros is garrisoned by the Night’s Watch, an ancient order of celibate men sworn to spend their lives defending the Wall. Although some of these men joined the Watch voluntarily, many were sent there as punishment for crimes they committed. Because the latter group makes up the majority of the Night’s Watch, the order has gained a poor reputation with many people from the South of Westeros, who believe that the Watch is a redundant order whose only purpose is to punish the worst criminals in the Seven Kingdoms. These men, who are often called “Black Brothers” or “Crows” for the black cloaks they wear, are divided into three categories: rangers, builders and stewards. The rangers are the combat arm of the Night’s Watch, and carry out patrols North of the Wall to perform reconnaissance and to fight the wildlings. The builders are responsible for maintaining the Wall and the three castles that the Watch still garrisons. The stewards are akin to servants, and perform all of the routine daily tasks so that the rangers can spend their time training for combat. Unlike the Roman Legionaries who garrisoned Hadrian’s Wall, the rangers of the Night’s Watch are not equipped to fight in pitched battles. This difference reflects the unique characteristics of the Wall in the North, as its massive size and effectiveness as a fortification allows the Watch to rely on it to protect them in the case of a wildling attack. Standing 700 feet tall, the Wall is nearly impossible to breach, thus the only threat the rangers face South of the Wall comes from wildling raiding parties who have scaled the enormous ice structure. This is why the rangers of the Watch are far more adept at fighting in small units than they are in large formations, though this expertise could also have developed given the dwindling numbers of men in the Watch.
 R.G. Grant, Warrior: A Visual History of the Fighting Man (New York: DK Publishing, 2010), 30.
 Patricia Southern, Roman Britain: A New History 55 BC-AD 450 (Gloucestershire: Amberly Publishing, 2011), 183.
 Grant, Warrior, 36-37.
 George R.R. Martin, The World of Ice and Fire (New York: Bantam Books Ltd., 2014), 476.
 Ibid., 475.