The extent to which the smaller structures on Hadrian’s Wall were standardised is widely celebrated. Both the adapted fortlets known as milecastles and the turrets strung out between them observed a regular spacing system and were built to a clearly defined plan. Although no two installations are identical, they are all very similar. This similarity has led to perceptions of a unity of purpose in which most interpretations of Hadrian’s Wall assume that the milecastles and turrets would function identically throughout its course. While this probably reflects the intentions of the designer and their military role, it is less likely to be a reliable guide to the day-to-day actuality of frontier life.
The groundplans and proposed reconstructions of the milecastles and turrets fit within a template of military architecture in which any given installation was built for a particular function and role. However, structure does not in itself define function, and ultimately it would be the soldiers within the various milecastles and turrets that would, to all intents and purposes, determine precisely how the individual installations were employed. This is particularly crucial for the milecastles, with their additional role as frontier gates. As such, milecastles represent a key node for ‘soldier’-‘civilian’ or ‘Roman’-‘barbarian’ interaction. In this context of contact, the militarism and use or abuse of power/authority by the milecastle garrison is critical in the portrayal and experience of the Roman empire in the frontier. Although the rank of the commanders on the ground within the milecastles is unknown, they are hardly likely to have been high ranking. This left the ultimate discretion concerning who could pass through a frontier (and under what terms) in the hands of relatively junior soldiers, almost certainly resulting in very discrepant experiences of empire. This paper will examine the relationship of functional interpretation of archaeological remains and theories relating to behaviour likely to have occurred at such sites, exploring the possible consequences of this astonishing arrangement.