The seventeenth century was an age of crowns, faith, and expanding empires-but above all, an age of war. Franco-English conflicts raged across Europe and the Atlantic world, fought in the name of Christianity by nations that often behaved with a ferocity worthy of the savagery they claimed to oppose. This book brings together the two great Franco-English wars of the seventeenth century, examining them not merely as military confrontations, but as cultural and ideological systems. Far from limiting itself to the narrow field of siege warfare, it places itself under the broader horizon of ars bellica-the learned and empirical science by which European aristocracies conceived, conducted, and justified war, while it was overwhelmingly the common people who died on the battlefields. At once rigorous and accessible, this volume invites readers to look beyond heroic myths and national legends, and to confront war as it was truly understood and practiced in early modern Europe.