This study examines the evolution of national and regional, cultural and political identities in that northern region of France which borders Belgium, over the two centuries which followed the French Revolution. During that time the region was transformed by the development of the industrial economy, population shifts, war and occupation, and numerous changes of political regime. Through an analysis of a wide range of issues, including language, regional and national political movements, educational policy, attitudes towards immigrants and the border, the press, trade unions, and the church - as well as the attitude of the French State - the author questions traditional interpretations of the process of national assimilation in France. At the same time he illustrates how the Franco-Belgian border, originally an arbitrary line through a culturally homogeneous region, became not only a significant marker for the identity of the French Flemish, but a real cultural division. TIMOTHY BAYCROFT is lecturer in French history, University of Sheffield.