Ostflucht

The Ostflucht (flight from the East) was the migration of Germans, in the later 19th century and early 20th century, from areas which were then eastern parts of Germany to more industrialized regions in central and western Germany. The migrants originated in East Prussia, West Prussia, Silesia and Posen; they moved to provinces along the Rhine and Ruhr rivers. Most of the migrants were ethnic Germans, but many migrants to the Ruhr were of Polish ethnicity, later known as Ruhrpolen.