In the eighteenth century, as wars between Britain, France, and their allies raged across the world, hundreds of thousands of people were captured, detained, or exchanged. They were shipped across oceans, marched across continents, or held in an indeterminate limbo. The Society of Prisoners challenges us to rethink the paradoxes of the prisoner of war, defined at once as an enemy and as a fellow human being whose life must be spared. Renaud Morieux redefines how we understand the notion of what a prisoner of war was before international legal and social conventions were introduced - in the eighteenth century, the distinction between a prisoner of war, a hostage, a criminal, and a slave was not always clear-cut. Morieux then uses war captivity as a lens through which to observe the eighteenth-century state, how it transformed itself, and why it endured. In so doing, he invites the reader to trace the history of the prisoners via a journey between Britain, France, the West Indies, and St Helena.