Surveillance studies often recall that Michel Foucault had identified the health crises of the plagues of the Ancien Régime as precursory moments in the establishment of modern surveillance. Episodes of civil wars are certainly another example. This study takes for object the capital of the kingdom of France at the siege of Paris, in 1589–1591, when Henry III and then Henri IV tried to reduce to their authority in the rebellious city, head of the Ultra-Catholic Ligue. This unprecedented experience of fear and generalized suspicion allows us to study how the usual mechanisms of social control are used for political ends, but also how new surveillance procedures emerge, based on the written word and a desire for rationalization. This article uses a wide range of sources, from municipal decisions to the reports of chroniclers, but relies mainly on the judicial archives of the Parlement and the Hôtel de Ville to draw up a social history as close as possible to ordinary Parisians. Taking a ground-level approach, the study is particularly interested in ordinary agents of urban control and forms of day-to-day and face-to-face surveillance. In this exceptional climate, the routine work of watching others in the neighborhood turned to political surveillance. The key actors were the Militia, whose action relied on the Parisians themselves, considered as “the eyes and ears” of the League authorities to know who the enemies were and to testify of the loyalty of the inhabitants.
