The ambiguous place that insurgents and guerrillas occupied between military and civil society helps to explain the fear that they aroused in others and the threat that they posed to the Revolutionary and Imperial state. They were not without precedent in European warfare: indeed, until the seventeenth century the sovereigns of invaded countries would routinely order their subjects to attack approaching armies, while in China as early as the fourth century BC governments and their advisors were already studying the techniques of counter-insurgency warfare. In moments of danger partisan warfare was a natural form of defence, especially in those regions where mountain ranges and coastal marshes provided natural protection, from the sand dunes of Dunkirk to the rocky passes of the Alps, the Dolomites and the Apennines; all offered cover for local men who knew the terrain and were not constrained by the laws of conventional warfare. Insurgency and lawlessness were natural bedfellows in frontier regions, and those to whom local people turned for protection in wartime had often served their apprenticeship as bandits or smugglers, terrorising passing traders, slipping unseen across national frontiers or tax boundaries, and learning the essential survival kit for any outlaw – a sense of place in a poorly mapped landscape, a knowledge of the goatherds’ tracks that were unpatrolled at night, a feel for those in the local community who might denounce or betray them.