Baltic states in the context of "Human Development Index"

The Slavs or Slavic people are a major ethnic group in Europe. They speak Slavic languages and preserve Slavic culture. There are 13 Slavic countries in Europe, which include: Poland, the Czech Republic, Slovakia, Russia, Belarus, Ukraine, Slovenia, Croatia, Bosnia and Herzegovina, Serbia, Montenegro, North Macedonia, and Bulgaria; the Slavs comprise a population of around 300 million people. There are three different Slavic ethnic groups: the West Slavs, the East Slavs, and the South Slavs; the Poles, Silesians, Kashubians, Sorbs, Czechs, and Slovaks are West Slavs; Russians, Belarusians, Ukrainians, and Rusyns are East Slavs; while Slovenes, Resians, Croats, Bosniaks, Serbs, Montenegrins, Torlakians, the Gorani, the Torbeši, Macedonians, and Bulgarians are South Slavs. Slavs are geographically distributed throughout the northern parts of Eurasia; they predominantly inhabit Central Europe, Eastern Europe, Southeastern Europe, and Northern Asia, though there is a large Slavic minority scattered across the Baltic states and Central Asia, and a substantial Slavic diaspora in the Americas, Western Europe, and Northern Europe.

Early Slavs lived during the Migration Period and the Early Middle Ages (approximately from the 5th to the 10th century AD), and came to control large parts of Central, Eastern, and Southeast Europe between the sixth and seventh centuries. Beginning in the 7th century, they were gradually Christianized. By the 12th century, they formed the core population of a number of medieval Christian states: East Slavs in the Kievan Rus', South Slavs in the Bulgarian Empire, the Principality of Serbia, the Duchy of Croatia and the Banate of Bosnia, and West Slavs in the Principality of Nitra, Great Moravia, the Duchy of Bohemia, and the Kingdom of Poland.

The East European Plain (also called the Russian Plain, or historically the Sarmatic Plain) is a vast interior plain extending east of the North European Plain, and comprising several plateaus stretching roughly from 25 degrees longitude eastward. It includes Volhynian-Podolian Upland on its westernmost fringe, the Central Russian Upland, and, on the eastern border, encompasses the Volga Upland. The plain includes also a series of major river basins such as the Dnieper Lowland, the Oka–Don Lowland, and the Volga Basin. At the southeastern point of the East European Plain are the Caucasus and Crimean mountain ranges. Together with the North European Plain (covering much of Belgium, the Netherlands, Denmark, Germany and Poland), and covering the Baltic states (Estonia, Latvia and Lithuania), European Russia, Belarus, Ukraine, Moldova, southeastern Romania, and, at its southernmost point, the Danubian Plain in Northern Bulgaria (including Ludogorie and Southern Dobruja), it constitutes the majority of the Great European Plain (European Plain), the greatest mountain-free part of the European landscape. The plain spans approximately 4,000,000 km (2,000,000 sq mi) and averages about 170 m (560 ft) in elevation. The highest point of the plain (480 metres (1,574.8 ft)) is in the Bugulma-Belebey Upland, in the Eastern part of the plain, in the elevated area by the Ural Mountains (priyralie).

Eastern Europe is a subregion of the European continent. As a largely ambiguous term, it has a wide range of geopolitical, geographical, ethnic, cultural and socio-economic connotations. Its eastern boundary is marked by the Ural Mountains, and its western boundary is defined in various ways. Narrow definitions, in which Central and Southeast Europe are counted as separate regions, include Belarus, Russia and Ukraine. In contrast, broader definitions include Moldova and Romania, but also some or all of the Balkans, the Baltic states, the Caucasus, and the Visegrád group. In Eastern Europe, Russia is the largest and most populous country.

The region represents a significant part of European culture; the main socio-cultural characteristics of Eastern Europe have historically largely been defined by the traditions of the Slavs, as well as by the influence of Eastern Christianity as it developed through the Eastern Roman Empire and the Ottoman Empire. Another definition was created by the Cold War, as Europe was ideologically divided by the Iron Curtain, with "Eastern Europe" being synonymous with communist states constituting the Eastern Bloc under the influence of the Soviet Union.

The revolutions of 1989, also known as the fall of communism, were a wave of liberal democratic movements that resulted in the collapse of most Marxist–Leninist governments in the Eastern Bloc and other parts of the world. This wave is sometimes referred to as the "autumn of nations", in reference to the revolutions of 1848 as the "spring of nations". The revolutions of 1989 were a key factor in the dissolution of the Soviet Union—one of the two superpowers—and abandonment of communist regimes in many parts of the world, some of which were violently overthrown. These events drastically altered the world's balance of power, marking the end of the Cold War and beginning of the post-Cold War era.

The earliest recorded protests, which led to the revolutions, began in Poland on 14 August 1980, the massive general strike which led to the August Agreements and establishment of Solidarity, the first and only independent trade union in the Eastern Bloc, whose peak membership reached 10 million. The main region of the 1989 revolutions was Central Europe, starting in Poland with the 1988 Polish strikes, and continued in Hungary, East Germany, Bulgaria, Czechoslovakia, and Romania. On 4 June 1989, Poland conducted the first elections that led to the dissolution of the communist government, with Solidarity winning an overwhelming victory, leading to the peaceful fall of communism in Poland. Influenced by Poland, Hungary organised round table-format talks and began dismantling its section of the Iron Curtain. In August 1989, over a quarter of the Baltic states population physically chained for 675 kilometres (419 mi) in the Baltic Way protesting the occupation by the Soviet Union, while the opening of a border gate between Austria and Hungary set in motion a peaceful chain reaction, in which the Eastern Bloc disintegrated. This led to mass demonstrations in cities of East Germany and the fall of the Berlin Wall in November 1989, which served as the symbolic gateway to German reunification in 1990. A feature common to these developments was the extensive use of campaigns of civil resistance, demonstrating popular opposition to the continuation of one-party rule and contributing to pressure for change. Romania was the only country in which citizens and opposition forces used violence to overthrow its communist regime, although Romania was politically isolated from the rest of the Eastern Bloc.

The Baltic states—Estonia, Latvia and Lithuania—were occupied and annexed by the Soviet Union in 1940 and remained under its control until its dissolution in 1991. For a period of several years during World War II, Nazi Germany occupied the Baltic states after it invaded the Soviet Union in 1941.

The initial Soviet invasion and occupation of the Baltic states began in June 1940 under the Molotov–Ribbentrop Pact, made between the Soviet Union and Nazi Germany in August 1939, before the outbreak of World War II. The three independent Baltic countries were annexed as constituent Republics of the Soviet Union in August 1940. Most Western countries did not recognise this annexation, and considered it illegal. In July 1941, the occupation of the Baltic states by Nazi Germany took place, just weeks after its invasion of the Soviet Union. The Third Reich incorporated them into its Reichskommissariat Ostland. In 1944, the Soviet Union recaptured most of the Baltic states as a result of the Red Army's Baltic Offensive, trapping the remaining German forces in the Courland Pocket until their formal surrender in May 1945.

The Eastern Front, also known as the Great Patriotic War in the Soviet Union and its successor states, and the German–Soviet War in modern Germany and Ukraine, was a theatre of World War II fought between the European Axis powers and Allies, including the Soviet Union (USSR) and Poland. It encompassed Central Europe, Eastern Europe, Northeast Europe (Baltics), and Southeast Europe (Balkans), and lasted from 22 June 1941 to 9 May 1945. Of the estimated 70–85 million deaths attributed to the war, around 30 million occurred on the Eastern Front, including 9 million children. The Eastern Front was decisive in determining the outcome in the European theatre of operations in World War II and is the main cause of the defeat of Nazi Germany and the Axis nations. Historian Geoffrey Roberts noted that "more than 80 percent of all combat during the Second World War took place on the Eastern Front".

The Axis forces, led by Germany, invaded the Soviet Union in Operation Barbarossa on 22 June 1941. Despite warnings and the deployment of Axis armies on his borders, Stalin refused to believe that Hitler would invade and forbade any defensive preparations. Thus the Soviets were caught completely unprepared. They were unable to halt deep Axis advances into Russia, which came close to seizing Moscow. However, the Axis failed to capture the city, and Hitler shifted his focus to the oil fields of the Caucasus the following year. German forces advanced into the Caucasus under Fall Blau ("Case Blue"), launched on 28 June 1942. The Soviets decisively defeated the Axis at the Battle of Stalingrad—the bloodiest battle in the war and arguably in all of history—making it one of the key turning points of the front. A second great Axis defeat, at the Battle of Kursk, crippled German offensive capabilities permanently and cleared the way for Soviet offensives. Several Axis allies defected to the Allies, such as Italy, Romania and Bulgaria. The Eastern Front concluded with the capture of Berlin, followed by the signing of the German Instrument of Surrender on 8 May, ending the Eastern Front and the war in Europe.

Central and Eastern Europe is a geopolitical term encompassing the countries in Northeast Europe (primarily the Baltics), Central Europe (primarily the Visegrád Group), Eastern Europe, and Southeast Europe (primarily the Balkans), usually meaning former communist states from the Eastern Bloc and Warsaw Pact in Europe, as well as from former Yugoslavia. Scholarly literature often uses the abbreviations CEE or CEEC for this term. The Organisation for Economic Co-operation and Development (OECD) also uses the term "Central and Eastern European Countries" (CEECs) for a group comprising some of these countries. This term is sometimes used as an alternative to the term "Eastern Europe," for more neutral grouping.