Pan-Germanism, movement whose goal was the political unification of all people speaking German or a Germanic language. Some of its adherents favoured the unification of only the German-speaking people of central and eastern Europe and the Low Countries (Dutch and Flemish being regarded as Germanic dialects). The movement had its roots in the desire for German unification stimulated by the war of liberation (1813–15) against Napoleon I and fanned by such early German nationalists as Friedrich Ludwig Jahn and Ernst Moritz Arndt. Advocates of the Grossdeutschland (Greater Germany) solution wished also to include the Germans of the Austrian Empire in one German nation, and others wished also to include the Scandinavians. Writers such as Friedrich List, Paul Anton Lagarde, and Konstantin Franz argued for German hegemony in central and eastern Europe—where German domination in some areas had begun as early as the 9th century ad with the Drang nach Osten (expansion to the East)—to ensure European peace. The notion of the superiority of the “Aryan race” proposed by Joseph-Arthur, comte de Gobineau, in his Essai sur l’inégalité des races humaines (1853–55; Essay on the Inequality of Human Races), influenced many Germans to extol the Nordic, or German, “race.”

The Pan-German Movement was organized in 1894, when Ernst Hasse, a professor at Leipzig and a member of the Reichstag (parliament), organized the Alldeutscher Verband (Pan-German League) on the basis of the loosely organized Allgemeiner Deutscher Verband (General German League) founded in 1891. Its purpose was to heighten German nationalist consciousness, especially among German-speaking people outside Germany. In his three-volume work, Deutsche Politik (1905–07), Hasse called for German imperialist expansion in Europe. Georg Schönerer and Karl Hermann Wolf articulated Pan-Germanist sentiments in Austria-Hungary and also attacked Slavs, Jews, and capitalism. These ideas did much to mold the mind of Adolf Hitler. Under the Weimar Republic (1919–33), Pan-Germanists continued to press for expansion; the most articulate and active force toward that end was Hitler and the Nazi Party. Expansionist propaganda was buttressed by a theory called geopolitics, which made history subject to a kind of geographical determinism. The expansionism preached by Munich professor Karl Haushofer, together with Ewald Banse, author of Raum und Volk im Weltkriege (1932; Germany, Prepare for War!), and Hans Grimm, author of Folk ohne Raum (1926; A Nation Without Room), was put into practice by Hitler in his annexation of Austria and the German-speaking area of Czechoslovakia and in the demands he made on Poland that led to the outbreak of World War II. Defeat in 1945 not only brought an end to Hitler’s Third Reich and its European hegemony but also resulted in the expulsion of Germans from formerly German areas of eastern Europe, the loss of a large portion of territory on Germany’s eastern frontier, and the division of the remaining German territory into two states.