This volume furnishes a unique insight into the role of the Early-Modern European military engineers in the construction and empowerment of sovereign authority, both in European kingdoms and republics and in the vast overseas dominions some of them acquired through the Expansion of Europe. From the Italian Renaissance to the Napoleonic Wars military engineers became indispensable as devisers of the complex systems of fortification needed to resist more and more powerful artillery. They were equally essential as managers of the technical business of besieging such fortifications. Though comparatively few in number, they could be the only numerate elite available to rulers. Often from an artistic background, and always with some mathematical training, they were natural polymaths capable of turning their hands to an astonishing range of activities.