French and Belgians sent 60,000 troops into the German industrial area of the Ruhr.
Took over factories, mines, railways.
Threw 15,000 Germans out of their homes and killed 130.
German government urged passive resistance and workers went on strike. To pay the workers, the government printed more money.
80% of German coal and iron was based in the Ruhr so Germany lost the income from this and also had to pay to import it.