Territorial evolution of Germany

The territorial changes of Germany include all changes in the borders and territory of Germany from its formation in 1871 to the present. Modern Germany was formed in 1871 when Otto von Bismarck unified most of the German states, with the notable exception of Austria, into the German Empire. After the First World War Germany lost about 10% of its territory to its neighbours and the Weimar Republic was formed. This republic included territories to the east of today's German borders.

The period of Nazi rule from the 1930s through the end of the Second World War brought significant territorial losses for the country. Nazi Germany initially expanded the country's territory dramatically and conquered most of Europe, though not all areas were added to Germany proper. The Nazis' fortunes changed after the failure of the invasion of Soviet Union. The Nazi regime eventually collapsed, and the Allies occupied Germany.

Immediately after the war, all territorial gains were reversed and pre-war Germany was split into British, French and American occupation zones in the northwest, west and south and a Soviet occupation zone in the centre; the capital Berlin was similarly divided into four sectors. The former eastern territories of Germany were ceded to Poland and the Soviet Union and the Oder and Neisse Rivers became Germany's new eastern boundary. This territory became Poland's so-called "Recovered Territories", while approximately one-third of East Prussia became Russia's Kaliningrad Oblast; virtually the entire German population in these areas was expelled or fled. In the west, the Saar area formed a French-controlled protectorate with limited autonomy, but its own citizenship laws.

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