The Field and the Forge offers a new approach to the pre-industrial past in Europe and the Mediterranean basin from the Roman Republic to the fall of Napoleon. Based on an original synthesis of ‘structural’ economic and demographic history with traditionally ‘event driven’ political and military history, it takes as its starting point E. A. Wrigley’s concept of ‘organic economies’ and their reliance on the land for energy and raw materials. The opening section considers the ensuing constraints on productivity, transportation, and the spatial organization of the economy. The second section analyses the constraints imposed by muscle-powered military technology and by the organic economy on the tactical, operational, and strategic use of armed force, and the consequences of the spread of firearms in recorded history’s first energy revolution. This is followed by an analysis of the military and economic constraints on the political integration of space through the formation of geographically extensive political units, and the volume concludes with a section on the demographic and economic consequences of the investment of manpower and resources in war. Existing accounts of organic economies emphasize their restricted potential to support economic and political development, but this volume also considers why so much potential remained unrealized. Endemic mass poverty curtailed demand, limiting incentives for investment and innovation, and keeping output growth below what was technologically possible. Resource shortages prevented rulers from establishing a fiscal apparatus capable of appropriating such resources as were physically available. But, economic inefficiency also created a pool of under-utilized resources that could potentially be mobilized in pursuit of political power. The volume gives an innovative account of this potential - and why it was realized in the ancient world rather than the medieval west - together with a new analysis of the gunpowder revolution and the inability of rulers to meet the consequential costs within the confines of an organic economy.