In January 1923 French and Belgian forces occupied Germany's Ruhr District and seized its prime industrial assets in lieu of unpaid reparations. This unilateral attempt to enforce the crumbling Versailles settlement precipitated a wider struggle for long-term control of Western Germany and ultimately for the very survival of the Weimar Republic. The Ruhr Crisis is the first comprehensive account of a definitive and mutually self-defeating confrontation, which marked one of the great untold tragedies of European history yet, paradoxically, sowed the seeds of Franco-German reconciliation after 1949. It demonstrates how and why the people of the Ruhr waged a grass-roots mass campaign of passive resistance against the invaders, and evaluates the human and political price of their ultimate failure. To this end, the author exploits a broad range of local and regional sources, many for the first time, to bring together the high politics of the crisis and intimate, often disturbing, accounts of the daily struggle in the mines, towns, and villages of the Ruhr. It is a ground-breaking contribution to the history of inter-war Germany.