East Prussia is the name of the former most eastern Prussian province, which existed until 1945 and whose extent (regardless of historically slightly changing border courses) roughly corresponds to the historical landscape of Prussia. The name was first used in the second half of the 18th century, when, in addition to the Duchy of Prussia with its capital Königsberg, which had been promoted to a kingdom in 1701, other previously Polish territories in the west (for example, the so-called Prussia Royal Share with Warmia and Pomerania) were added to Brandenburg-Prussia and formed the new province of West Prussia.
Nowadays, the territory of the former Prussian province belongs mainly to Russia (Kaliningrad Oblast) and Poland (Warmia-Masuria Voivodeship). The former so-called Memelland (also Memelgebiet, lit. Klaipėdos kraštas) first became part of Lithuania in 1920 and again from 1945.
The Baltic States is a region in the north-east of Europe and is composed of the three states Estonia, Latvia and Lithuania. The Baltic States are inhabited by almost 6 million people.
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).
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.
Estonia is a country in north-eastern Europe. It is inhabited by around 1.3 million people and borders Latvia, Russia and the Baltic Sea. The most populous city and capital is Tallinn.
Today's Estonian state only regained its political independence in 1991 as a result of the so-called “Singing Revolution” in the Baltic states and in the wake of the collapse of the Soviet Union. Estonian independence was first proclaimed in 1918 and achieved through the “Estonian War of Independence” (1918-1920). As early as 1940, this first Estonian state was replaced by the “Estonian Soviet Socialist Republic”, which was founded under Soviet occupation. With an interruption due to the German occupation during the Second World War (1941-1944) and with slightly different borders, it was a constituent republic of the Soviet Union until 1991. Before 1918, the territory of present-day Estonia was part of the Russian Empire, with its northern part forming the Baltic Governorate of Estonia and its southern part the northern half of the Baltic Governorate of Livonia. In the High and Late Middle Ages and at the beginning of the early modern period, parts of today's country were also under Swedish, Danish and Polish rule, while the Livonian part was also under the sovereignty of the Teutonic Order until 1561.
Estonia has been part of the European Union and NATO since 2004.
Latvia is a Baltic state in the north-east of Europe and is home to about 1.9 million inhabitants. The capital of the country is Riga. The state borders in the west on the Baltic Sea and on the states of Lithuania, Estonia, Russia and Belarus. Latvia has been a member of the EU since 01.05.2004 and only became independent in the 19th century.
Lithuania is a Baltic state in northeastern Europe and is home to approximately 2.8 million people. Vilnius is the capital and most populous city of Lithuania. The country borders the Baltic Sea, Poland, Belarus, Russia and Latvia. Lithuania only gained independence in 1918, which the country reclaimed in 1990 after several decades of incorporation into the Soviet Union.