In the five hundred years covered by this volume there was scarcely a year which passed without either war or some open demonstration of hostility between the many sovereign powers which governed Europe. States and peoples lived under the shadow of war, were ceaselessly prompted to consider the possibility of war, had to find ways of dealing with the consequences of war. This volume in the Origins of the Modern State in Europe series focuses on the crucial role of war in the formation of state systems. It starts from the assumption that interstate rivalries and conflicts were at the heart not only of the demarcation of territories, but also of the ever-growing need to mobilize resources for warfare. Institutionalization was consequently highly dependent on such competition. It was for military reasons, and with military aims, that the state secured control of time and space, both at sea and on land. The Origins of the Modern State in Europe series arises from an important international research programme sponsored by the European Science Foundation. The aim of the series, which comprises seven volumes, is to bring together specialists from different countries, who reinterpret from a comparative European perspective different aspects of the formation of the state over the long period from the beginning of the thirteenth to the end of the eighteenth century. One of the main achievements of the research programme has been to overcome the long-established historiographical tendency to regard states mainly from the viewpoint of their twentieth-century borders.