Soviet occupation zone in Germany in the context of "Potsdam Agreement"

East Germany, officially the German Democratic Republic (GDR), was a country in Central Europe from its formation on 7 October 1949 until its reunification with West Germany (Federal Republic of Germany) on 3 October 1990. Until 1989, it was generally viewed as a communist state and described itself as a socialist workers' and peasants' state. The economy of the country was centrally planned and state-owned. Although the GDR had to pay substantial war reparations to the Soviet Union, its economy became the most successful in the Eastern Bloc.

Before its establishment, the country's territory was administered and occupied by Soviet forces following the Berlin Declaration abolishing German sovereignty in World War II. The Potsdam Agreement established the Soviet-occupied zone, bounded on the east by the Oder–Neiße line. The GDR was dominated by the Socialist Unity Party of Germany (SED), a communist party, before being democratized and liberalized amid the revolutions of 1989; this paved the way for East Germany's reunification with West Germany. Unlike the government of West Germany, the SED did not see its state as the successor to the German Reich (1871–1945). In 1974, it abolished the goal of unification in the constitution. The SED-ruled GDR was often described as a Soviet satellite state; historians describe it as an authoritarian regime.

Petersberg Citadel (German: Zitadelle Petersberg) in Erfurt, central Germany, is one of the largestand best-preserved town fortresses in Europe. The citadel was built on Petersberg hill, in the north-western part of the old town centre from 1665, when Erfurt was governed by the Electorate of Mainz. It is surrounded by over two kilometres of stone walls and is 36 hectares in size.

Erfurt has also been ruled by Sweden, Prussia, Napoleon, the German Empire, the Nazis, and post-World War II Soviet occupying forces, and it was part of the German Democratic Republic (East Germany). All of these regimes used Petersberg Citadel and had an influence on its development. The baroque fortress was in military use until 1963. Since German reunification in 1990, the citadel has undergone significant restoration and it is now open to the public as a historic site. Its maze of underground passageways are also open to visitors and the fortress bakery (1832) is again in working order.

The Soviet Military Administration in Germany (Russian: Советская военная администрация в Германии, СВАГ; Sovyetskaya Voyennaya Administratsiya v Germanii, SVAG; German: Sowjetische Militäradministration in Deutschland, SMAD) was the Soviet military government, headquartered in Berlin-Karlshorst, that directly ruled the Soviet occupation zone in Germany from the German surrender in May 1945 until after the establishment of the German Democratic Republic (GDR) in October 1949.

According to the Potsdam Agreement in 1945, the SMAD was assigned the eastern portion of present-day Germany, consisting mostly of central Prussia. Prussia was dissolved by the Allies in 1947 and this area was divided between several German states (Länder). German lands east of the Oder-Neisse line were annexed by Soviet Union or granted to Poland, and Germans living in these areas were forcibly expelled, having had their property expropriated and been robbed of most of their belongings whilst in transit to the American, British, and Soviet zones.

The British occupation zone in Germany (German: Britische Besatzungszone Deutschlands) was one of the Allied-occupied areas in Germany after World War II. The United Kingdom – also representing the other Commonwealth countries – was one of the three major Allied powers that defeated Nazi Germany. By 1945, the Allies had divided the country into four occupation zones: British, Soviet, American and French lasting until 1949, whence the new country of West Germany was established. Out of all the four zones, the British had the largest population and contained within it the heavy industry region, the Ruhr, as well as the naval ports and Germany's coast lines.

The Reichsmark (German: [ˈʁaɪçsˌmaʁk] ; sign: ℛ︁ℳ︁; abbreviation: RM) was the currency of Germany from 1924 until the fall of Nazi Germany in 1945, and in the American, British and French occupied zones of Germany, until 20 June 1948. The Reichsmark was then replaced by the Deutsche Mark, to become the currency of West Germany and then all of Germany after the 1990 reunification. The Reichsmark was used in the Soviet occupation zone in Germany until 23 June 1948, where it was replaced by the East German mark. The Reichsmark was subdivided into 100 Reichspfennig (Rpf or ℛ︁₰). The Mark is an ancient Germanic weight measure, traditionally a half pound, later used for several coins; Reich (realm in English) comes from the official name for the German state from 1871 to 1945, Deutsches Reich.