Iron Age Hillfort Defences and the Tactics of Sling Warfare

The defensive function of Iron Age hillforts has been disputed, on the grounds that they are poorly suited to military purposes and because recent models of Iron Age society emphasise symbolic display, community-building and boundaries, rather than warfare. Although excavation of hillfort interiors provides evidence of varied functions, these do not explain the features of the surrounding banks and ditches: in this study, the functions of the enclosing works are argued to be distinct from the functions of the hillfort interiors.
Pebbles found in large numbers at hillforts are interpreted as sling-stones, slings having been widely used as weapons in ancient times, and several writers have suggested that Middle Iron Age modifications to hillfort defences improved their capability against attack by stoning. However, there is little information on sling performance in the context of hillforts.
An experimental examination of these issues is described. Seven slingers cast a total of 1278 stones at a target placed in 14 positions on the defences of a hillfort, representing attack and defence of a univallate rampart and of a bivallate dump rampart. The most practiced slinger had hit-rates of 29% against a man-sized target and 68% against a target representing a group of six attackers. His effective range was over 70m. Attackers scored more hits in the univallate case, and defenders in the bivallate case. Distance to target was the main predictor of hit-rate, height being advantageous only at marginal range. Observations include the need for context-specific training and that dead ground in the outer ditch was not a defensive disadvantage.
The results were used to model several tactical scenarios, including direct assaults and barrages of stones. In general the defenders had the advantage, especially in the bivallate case, the time of exposure to defensive slinging being a key factor. Speed, surprise and superior slinging effectiveness on the part of attackers could overcome the disadvantage, but the availability of reinforcements would determine the outcome in favour of the defence in the bivallate case. Other factors, including shields, parapets and entrance designs are discussed, as are methodological issues and problems of interpretation.
The study concludes that defence remains the most persuasive functional explanation for the features of the enclosing works of hillforts.