Research contributions – Contemporary witness reports on the culture and history of the Germans in Eastern Europe in the 20th century

Silesia (Polish: Śląsk, Czech: Slezsko) is a historical landscape, which today is mainly located in the extreme southwest of Poland, but in parts also on the territory of Germany and the Czech Republic. By far the most significant river is the Oder. To the south, Silesia is bordered mainly by the Sudeten and Beskid mountain ranges. Today, almost 8 million people live in Silesia. The largest cities in the region are Wrocław, Opole and Katowice. Before 1945, most of the region was part of Prussia for two hundred years, and before the Silesian Wars (from 1740) it was part of the Habsburg Empire for almost as many years. Silesia is classified into Upper and Lower Silesia.

Ostpreußen ist der Name der ehemaligen, bis 1945 bestehenden östlichsten preußischen Provinz, deren Ausdehnung (ungeachtet historisch leicht wechselnder Grenzverläufe) ungefähr der historischen Landschaft Preußen entspricht. Die Bezeichnung kam erst in der zweiten Hälfte des 18. Jahrhunderts in Gebrauch, als neben dem 1701 zum Königreich erhobenen Herzogtum Preußen mit seiner Hauptstadt Königsberg weitere, zuvor polnische Gebiete im Westen (beispielsweise das sog. Preußen Königlichen Anteils mit dem Ermland und Pommerellen) zu Brandenburg-Preußen kamen und die neue Provinz Westpreußen bildeten.
Heutzutage gehört das Gebiet der ehemaligen preußischen Provinz überwiegend zu Russland (Oblast Kaliningrad) und Polen (Woiwodschaft Ermland-Masuren). Das ehemalige sog. Memelland (auch Memelgebiet, lit. Klaipėdos kraštas) kam erstmals 1920 und erneut ab 1945 zu Litauen.

Poland is located on the Baltic Sea and is the largest state (population in 2023: 37,636,508, area: 313,964 km²) in East Central Europe. The name of the state is derived from the West Slavic Polans, who brought more and more territories under their rule from the 9th century onwards, which were known as Duchy of Poland in the 10th century. Under Mieszko (ca. 960-992), the extent of the country reached approximately its current borders. He was at times subject to tribute to the German Emperor, at least for parts of his land. Poland probably adopted Christianity in 966 and from 1025 it was a kingdom. Between 1138 and 1295, the country was fragmented as a result of inheritance disputes. The extinction of the ruling Piast dynasty led to a Polish-Hungarian personal union in 1370, which was replaced by a Polish-Lithuanian dual monarchy as early as 1386 due to pressure from the Polish nobility. The growing role of the nobility resulted in an elective monarchy in 1572. However, the disunity of the nobility led to the three partitions of Poland (1772-1795) between Prussia, Russia and the Habsburg Monarchy. Poland only became independent after the end of the First World War in 1918 and lost its independence in 1939 after the German attack from the west at the beginning of the Second World War and the Russian invasion from the east. From 1945-1989 it was a satellite state of the Soviet Union. Poland has been a member of the European Union since 2004.

Hungary is a country in Central Europe, whose capital is Budapest. The country is home to about 10 million people and was part of the so-called Habsburg Empire for several centuries. Hungary has been a member of the European Union since 01.05.2004. The Danube is the largest river in the country.

Czechoslovakia was a state existing between 1918 and 1992 with changing borders and under changing names and political systems, the former parts of which were absorbed into the present-day states of the Czech Republic, Slovakia and Ukraine (Carpathian Ukraine, already occupied by Hungary in 1939, from 1945 to the Soviet Union). After 1945, Czechoslovakia was under the political influence of the Soviet Union, was part of the so-called Eastern Bloc as a satellite state, and from 1955 was a member of the Warsaw Pact. Between 1960 and 1990, the communist country's official name was Czechoslovak Socialist Republic (abbreviated ČSSR). The democratic political change was initiated in 1989 with the Velvet Revolution and resulted in the establishment of the independent Czech and Slovak republics in 1992.

The Russian Federation is the largest territorial state in the world and is inhabited by about 145 million people. The capital and largest city is Moscow, with about 11.5 million inhabitants, followed by St. Petersburg with more than 5.3 million inhabitants. The majority of the population lives in the European part of Russia, which is much more densely populated than the Asian part.

Since 1992, the Russian Federation has been the successor state to the Russian Soviet Republic (Russian Socialist Federative Soviet Republic, RSFSR), by far the largest constituent state of the former Soviet Union. It is also the legal successor of the Soviet Union in the sense of international law.

Romania is a country in southeastern Europe with a population of almost 20 million people. The capital of the country is Bucharest. The state is situated directly on the Black Sea, the Carpathian Mountains and borders Bulgaria, Serbia, Hungary, Ukraine and Moldova. Romania was established in 1859 from the merger of Moldova and Wallachia. Romania is home to Transylvania, the central region for the German minority there.