Medieval Strategy and the Economics of Conquest

Medieval military and political leaders were well able to make rational plans for how to use armed forces in order to achieve political aims. Their strategic plans, however, had to reflect their circumstances. Kings and princes had relatively small fiscal reserves, and fortifications were widespread. The strategic balance favored the defense in general, and in particular made actual conquest of an area difficult. But if offensive warfare, and even outright conquest, could be made to pay for itself with the profits of plunder and the value of land acquired, that would render the fiscal weakness of medieval states largely moot. Historians have not yet examined this question in a quantitative fashion, using the medieval sources to compare the financial costs of individual campaigns (particularly sieges) with the fiscal benefits derived from conquest. By doing so it is possible to show that war could be made to pay for war, especially in urbanized areas and in times and places where it was permitted to enslave enemy populations.