Hadrian Wall - Purpose of Construction

Purpose of Construction

Hadrian's Wall was likely planned before Roman Emperor Hadrian's visit to Britain in 122. According to restored sandstone fragments found in Jarrow that date from 118 or 119, it was Hadrian's wish to keep "intact the empire," which had been imposed upon him by "divine instruction." The fragments then announce the building of the wall. It is entirely possible that, on his arrival in Britain in 122, one of the stops on his itinerary was the northern frontier and an inspection of the progress of the wall as it was being built.

Although Hadrian's biographer wrote "(Hadrian) was the first to build a wall 80 miles long to separate the Romans from the barbarians", reasons for the construction of the wall vary, and no recording of any exact explanation survives. However, a number of theories have been presented by historians, primarily centreing around an expression of Roman power and Hadrian's policy of defence before expansion. For example, on his accession to the throne in 117, Hadrian had been experiencing rebellion in Roman Britain and from the peoples of various conquered lands across the Empire, including Egypt, Israel, Libya and Mauretania. These troubles may have had a hand in Hadrian's plan to construct the wall, and his construction of limes in other areas of the Empire, but to what extent is unknown.

Scholars also disagree over how much of a threat the inhabitants of northern Britain actually presented, and whether there was any more economic advantage in defending and garrisoning a fixed line of defences like the Wall over simply conquering and annexing what has become the Scottish Lowlands and manning the territory with a loose arrangement of forts. The Limes of Rome were never expected to stop whole tribes from migrating or entire armies from invading, and while a frontier protected by a palisade or stone wall would surely help curb cattle-raiders and the incursions of other small groups, the economic viability of constructing and constantly manning a 72-mile (116 km) long boundary along a sparsely populated border to stop small-scale raiding is dubious.

Another possible explanation for the erection of the great wall is the degree of control it would have provided over immigration, smuggling, and customs. Limes did not strictly mark the boundaries of Rome, with Roman power and influence often extending beyond its walls. People inside and beyond the limes travelled through it each day when conducting business, and organized check-points like those offered by Hadrian's Wall provided good opportunities for taxation. With watch towers only a short distance from gateways in the limes, patrolling legionaries would have been able to keep track of entering and exiting natives and Roman citizens alike, charging customs dues, and checking for smuggling activity.

Another theory is of the simpler variety—Hadrian's Wall was, if not wholly, at least partially, constructed to reflect the power of Rome, and was used as a political point by Hadrian. Once its construction was finished, it is thought to have been covered in plaster and then white-washed, its shining surface able to reflect the sunlight and be visible for miles around.