Former eastern territories of Germany

The former eastern territories of Germany (German: Ehemalige deutsche Ostgebiete) refer in present-day Germany to those territories (provinces or regions) east of the current eastern border of Germany (the Oder–Neisse line) which historically had been considered German and which were lost by Germany after World War II.[1] Territories acquired by Poland after World War II were officially called there the Recovered Territories (but the term was used inconsistently in regard to the former Free City of Danzig).[2] These territories had been ruled as part of Poland by the Piast dynasty in the High Middle Ages with the exception of East Prussia which originally was inhabited by Old Prussians and came under Polish suzerainty in the Late Middle Ages. The northern half of historic East Prussia was, however, made part of the Soviet Union, with the former Klaipeda Region reattached to the Lithuanian Soviet Socialist Republic, and the rest being annexed by the Russian Soviet Federative Socialist Republic as the Kaliningrad Oblast, now forming a Russian exclave.

  Territory lost after World War I
  Territory lost after World War II
  Present-day Germany

In contrast to the lands awarded to the restored Polish state by the Treaty of Versailles, the territories lost after World War II were either almost exclusively inhabited by Germans before 1945 (the bulk of East Prussia, the bulk of Lower Silesia, Farther Pomerania, and the parts of Western Pomerania, Lusatia and Neumark awarded to Poland) or mixed German-Polish with a German majority (Posen-West Prussia Border March, Lauenburg and Bütow Land, the southern and western rim of East Prussia, Ermland, West Upper Silesia, and the part of Lower Silesia east of the Oder). The German population of the territories that had not fled in 1945 was expropriated and expelled, forming the majority of the Germans expelled from Eastern Europe.

The post-war border between Germany and Poland along the Oder–Neisse line was defined in August 1945 by the Potsdam Agreement of the leaders of the three Allied Powers, the Soviet Union, the United Kingdom, and the United States; and was formally recognized by East Germany in 1950, by the Treaty of Zgorzelec, under pressure from Stalin. In 1952, recognition of the Oder–Neisse Line as a permanent boundary was one of Stalin's conditions for the Soviet Union to agree to a reunification of Germany (see Stalin Note). The offer was rejected by West German Chancellor Konrad Adenauer. The then official West German government position on the status of former eastern territories of Germany east of the Oder and Neisse rivers was that the areas were "temporarily under Polish [or Soviet] administration", because the border regulation at the Potsdam Conference had been taken as preliminary provisions to be revisited at a final peace conference, which, also due to the Cold War had been indefinitely postponed.;[3] however by 1970, West Germany recognised the Oder-Neisse line as the western boundary of Poland by the Treaty of Warsaw; and in 1973, the Federal Constitutional Court acknowledged the capability of East Germany to negotiate the Treaty of Zgorzelec as an international agreement binding as a legal definition of its boundaries. In signing the Helsinki Final Act in 1975, both West Germany and East Germany recognised the existing boundaries of post-war Europe, including the Oder-Neisse line, as valid in international law.

In 1990, as part of the reunification of Germany, West Germany accepted clauses in the Treaty on the Final Settlement With Respect to Germany whereby Germany renounced all claims to territory east of the Oder–Neisse line.[4] Germany's recognition of the Oder–Neisse line as the border was formalised by the re-united Germany in the German–Polish Border Treaty on 14 November 1990; and by the repeal of Article 23 of the Basic Law for the Federal Republic of Germany under which German states outside the Federal Republic could formerly have declared their accession.

Germany went from a territory of 468,787 km2[5] in 1937 to 357,022 km2[6] after the reunification of Germany (1990).[7]