For over half a century, discussion of the relationship between military finance, organisation, and state development has been dominated by the contested concept of a ‘military revolution’; the belief that there were one or a few periods of fundamental change that transformed both war and wider European history. More recently, this has been supplemented by the idea of smaller, but more frequent ‘revolutions in military affairs’ (RMAs) as individual military organisations respond to, or anticipate, changes made by their likely opponents. Technology is generally considered to drive both forms of ‘revolution’, as innovative weaponry and institutional practice transform war, rendering older models ineffective and obsolete. Change flows through a series of chain reactions, as states adapt to new conditions, modifying their structures to sustain and direct altered armed forces, and revising their forms of interaction with society both to extract the necessary resources and to legitimate their use in war-making.