The aim of this book is to examine the rise, success and transformations of military enterprise – warfare organized and waged by private contractors – in early modern Europe (c.1500–1700). Military enterprise as it is discussed here amounts to a lot more than hiring mercenaries to serve in the ranks of a state-run army or using privateers to supplement or stand in for the state’s navy. Enterprise includes a more extensive delegation of responsibility and authority to include the supply of food, clothes and equipment to troops, and the manufacturing and distribution of munitions and weapons. Warship and fortress building were outsourced, as were entire naval operations. Garrisoning and siege-works were put out to contract. A large part of this process did involve the hiring and maintenance of soldiers or sailors, but the terms of many of the recruitment contracts drawn up with the field and unit commanders reveal significant differences from those before or after this period. Moreover the way in which these commanders interpreted their authority and autonomy in waging war on behalf of their employers was significantly changed. They acted through their own creditors to raise the funds required for recruitment and military operations, and they drew on networks of private manufacturers, merchants and transport operatives to ensure that their troops were fed and equipped. Some fundamental aspects of the financing of war were placed in the hands of private military contractors or their agents, who also ensured that their credit and costs were recovered, by force if necessary, even when the army was on the territory of its notional employer.