Over the course of Louis XIV's 54-year reign (1661-1715), Western Europe witnessed thirty-six years of conflict. Siege warfare figures significantly in this accounting, for extended sieges quickly consumed short campaign seasons and prevented decisive victory. The resulting prolongation of wars and the cost of besieging dozens of fortresses with tens of thousands of men forced "fiscal-military" states to continue to elevate short-term financial considerations above long-term political reforms; Louis’s wars consumed 75% or more of the annual royal budget. Historians of 17th century Europe credit one French engineer – Sébastien le Prestre de Vauban – with significantly reducing these costs by toppling the impregnability of 16th century artillery fortresses. Vauban perfected and promoted an efficient siege, a "scientific" method of capturing towns that minimized a besieger's casualties, delays and expenses, while also sparing the town's civilian populace. How thoroughly Vauban's siege legacy was accepted by the end of Louis's reign is the focus of this study.A quantitative survey of the 115 sieges in the War of the Spanish Succession (1701-1714) places the anecdotally-based conventional wisdom on a more sure footing by setting Vauban's offensive revolution in a broader chronological context. Abandoning the narrow biographical accounts of national figures (Vauban and the English Duke of Marlborough in particular), we discover a larger picture that highlights the many challenges engineers faced when applying his theory to the reality of combat. Focusing on the Flanders theater (1702-1712), we find that the most important elements of Vauban's siege attack were not only ignored, but actively opposed by the most successful French and Allied generals. These commanders – the most famous among them Marlborough, Prince Eugene of Savoy, and the Duke of Villars – are examples of a widespread reaction against Vauban's humanitarian attempts to rationalize warfare. Generals consistently rejected Vauban's goals and captured strong fortresses with brute force rather than finesse; they accepted higher casualties in order to avoid delays. In this early modern discourse over how wars were to be waged, the brute force community emerged victorious. Their acceptance of high casualties and reliance on overwhelming firepower has influenced Western military strategy ever since.