A magnificent and timely examination of an age of fear, subversion, suppression and espionage, Adam Zamoyski explores the attempts of the governments of Europe to police the world in a struggle against obscure forces, seemingly dedicated to the overthrow of civilisation.

The advent of the French Revolution confirmed the worst fears of the rulers of Europe. They saw their states as storm-tossed vessels battered by terrible waves coming from every quarter and threatened by horrific monsters from the deep. Rulers' nerves were further unsettled by the voices of the Enlightenment, envisaging improvement only through a radical transformation of existing structures, with undeniable implications for the future role of the monarchy and the Church.

Napoleon's arrival on the European stage intensified these fears, and the changes he wrought across Europe fully justified them. Yet he also brought some comfort to those rulers who managed to survive: he had tamed the revolution in France and the hegemony he exercised over Europe was a kind of guarantee against subversion. Once Napoleon was toppled, the monarchs of Europe took over this role for themselves.