Claude Langlois's work on the French Revolution captures the experience of ordinary people in the country as a whole. Against an interpretation that sees the Revolution as resulting in a secular, modernized France, he emphasizes the ambiguity and uncertainties of the outcome. He is above all interested in assessing the impact of the Revolution on the Church. Although the Revolution had a profound impact on the personnel, landscape, finances, and politics of the Church, the Concordat created the conditions for recovery. There were restorations in pastoral care and practices but in addition, there were also ruptures, especially in the long term. Alongside a nineteenth century of unexpected piety, there were also regions and groups of low practice and indifference. The article also discusses Langlois's contributions to the political history of the coup of 1799, and to population studies.