The Soviet Union (SU or USSR) was a state in Eastern Europe, Central and Northern Asia that existed from 1922 to 1991. It emerged from the so-called Soviet Russia, the successor state of the Russian Empire. The Russian Soviet Republic formed the core of the union and at the same time its largest part, with further constituent republics added. Their number varied over time and was related to the occupation of other countries (Estonia, Latvia, Lithuania), Soviet republics that existed only for a short time (Karelo-Finlandia) or the division or merger of Soviet republics. In addition, there were numerous autonomous republics or other territorial units with an autonomy status that was essentially limited to linguistic autonomy for minorities.
Before its formal dissolution, the USSR consisted of 15 Soviet republics with a population of approximately 290 million people. At around 22.4 million km², it was the largest territorial state in the world at the time. The Soviet Union was a socialist soviet republic with a one-party system and an absence of separation of powers.
The German Empire was a state in Central Europe that existed from 1871 to 1945. The period from its founding until 1918 is called the German Empire, then followed the period of the Weimar Republic (1918/1919-1933) and the National Socialism (so-called Third Reich) from 1933 to 1945. 01.01.1871 is considered the day of the foundation of the German Reich.
The Russian Empire (also Russian Empire or Empire of Russia) was a state that existed from 1721 to 1917 in Eastern Europe, Central Asia and North America. The country was the largest contiguous empire in modern history in the mid-19th century. It was dissolved after the February Revolution in 1917. The state was regarded as autocratically ruled and was inhabited by about 181 million people.
Austria-Hungary (Hungarian: Osztrák-Magyar Monarchia), also known as Imperial and Royal Hungary Monarchy, was a historical state in Central and Southeastern Europe that existed from 1867 to 1918.
Poland is a state in Central Eastern Europe and is home to approximately 38 million people. The country is the sixth largest member state of the European Union. The capital and biggest city of Poland is Warsaw. Poland is made up of 16 voivodships. The largest river in the country is the Vistula (Polish: Wisła).
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.
