Several definitions of Eastern Europe exist today, but they often lack precision or are extremely general. These definitions vary both across cultures and among experts, even political scientists, recently becoming more and more imprecise.
The Ural Mountains, Ural River, and the Caucasus Mountains are the geographical land border of the eastern edge of Europe. In the west, however, the cultural and religious boundaries of "Eastern Europe" are subject to considerable overlap and, most importantly, have undergone historical fluctuations, which make a precise definition of the western boundaries of Eastern Europe and the geographical midpoint of Europe somewhat difficult.
Eurovoc, a multilingual thesaurus maintained by the Publications Office of the European Union, provides entries for "23 EU languages" (Bulgarian, Croatian, Czech, Danish, Dutch, English, Estonian, Finnish, French, German, Greek, Hungarian, Italian, Latvian, Lithuanian, Maltese, Polish, Portuguese, Romanian, Slovak, Slovenian, Spanish and Swedish) plus languages of candidate countries (Albanian, Macedonian and Serbian). Of these, those in italics are classified as "Eastern Europe" in this source. Other official web-pages of the European Union classify some of the above-mentioned countries as strictly Central European (Hungary, Poland, Slovakia, Czech Republic, Slovenia).
One view of the present boundaries of Eastern Europe came into being during the final stages of World War II. The area eventually came to encompass all the European countries which were under Soviet influence. Countries which had communist governments in the postwar era (1945-1991), and neutral countries were classified by the nature of their political regimes.
The Cold War increased the number of reasons for the division of Europe into two parts along the borders of NATO and Warsaw Pact states. (See: the Cold War section). The economic organisation connecting the countries was the Council for Mutual Economic Assistance.
Since the Great Schism of 1054, Europe has been divided between Roman Catholic and Protestant churches in the West, and the Eastern Orthodox Christian (many times incorrectly labeled "Greek Orthodox") churches in the east. Due to this religious cleavage, Eastern Orthodox countries are often associated with Eastern Europe. A cleavage of this sort is, however, often problematic; for example, Greece is overwhelmingly Orthodox, but is very rarely included in "Eastern Europe", for a variety of reasons.
The fall of the Iron Curtain brought the end of the East–West division in Europe, but this geopolitical concept is sometimes still used for quick reference by the media.
EuroVoc, National Geographic Society, Committee for International Cooperation in National Research in Demography, STW Thesaurus for Economics and most other modern sources place the Baltic states in Northern Europe whereas the CIA World Factbook & UNESCO place the region in Eastern Europe with a strong assimilation to Northern Europe. The Baltic states have seats in the Nordic Council as observer states. They also are members of the Nordic-Baltic Eight whereas Eastern European countries formed their own alliance called the Visegrád Group. The Northern Future Forum, the Nordic Investment Bank and Nordic Battlegroup are other examples of Northern European cooperation that includes the three Baltic states that make up the Baltic Assembly. Estonia
The Caucasus nations are often included in definitions of Eastern Europe or histories of Eastern Europe. However, the extent of their geographic or political affiliation with Europe varies by country. All three states are members of the European Union's Eastern Partnership program and the Euronest Parliamentary Assembly. On 12 January 2002, the European Parliament noted that Armenia and Georgia may enter the EU in the future. Georgia — in modern geography, Georgia has been classified as entirely part of Eastern Europe, or as having territory in both Eastern Europe and Asia. Under the European Union’s geographic criteria, Georgia is viewed as part of Eastern Europe and is the only Caucasus country to be actively seeking EU membership.
Armenia — geographically, Armenia is thought to fall outside of Europe’s boundaries; however, it is often associated with Eastern Europe due to being Christian, as well as due to its political and historical ties to the continent. It is a member of Council of Europe and Eurocontrol.
Azerbaijan — Shiite Muslim Azerbaijan is culturally oriented more toward Central Asia; however, it is a highly secular country and at least parts of its northern territories are geographically inside Eastern Europe.
There are 3 de-facto independent Republics with limited recognition in the Caucasus region. All 3 states participate in the Community for Democracy and Rights of Nations: Abkhazia
Several other former Soviet republics may be considered part of Eastern Europe Russia is a transcontinental country where the Western part is in Eastern Europe and the rest is in Asia.
Kazakhstan is a transcontinental country, predominantly in Asia, with a relatively small section in Europe.
Disputed states: Transnistria
The term "Central Europe" is often used by historians to designate states formerly belonging to the Holy Roman Empire or the Polish-Lithuanian Commonwealth, including parts of modern-day Belarus and Ukraine. "Central Europe" thus overlaps with "Eastern Europe." The following countries are labeled Eastern European by some commentators and as Central European by others. Austria
Slovenia (most often placed in Central Europe but sometimes in Southeastern Europe)
Most Southeastern European states did not belong to the Eastern Bloc (save Bulgaria, Romania, and for a short time, Albania) although some of them were represented in the Cominform. Only some of them can be included in the classical former political definition of Eastern Europe. Some can be considered part of Southern Europe. However, most can be characterized as belonging to South-eastern Europe, but some of them may also be included in Central Europe or Eastern Europe. Albania belongs to Southeastern Europe.
Bosnia and Herzegovina
Bulgaria is in the central part of the Balkans; geographically belongs to Southern/Southeastern Europe and sometimes included in the North-Eastern Mediterranean, but can also be included in Eastern Europe in the Cold War.
Cyprus is geographically situated in the eastern Mediterranean, off the coast of west Asian mainland, however due to its political, cultural, and historical ties to Europe, it is often regarded as part of Southern, and Southeastern Europe.
Greece is a rather unusual case and may be included, variously, in Western, Southeastern or Southern Europe.
Macedonia belongs to Southeastern Europe.
Montenegro belongs to Southeastern Europe.
Romania can be included in Eastern Europe in the Cold War context, but is commonly referred to as belonging to Southeastern Europe or Central Europe.
Serbia is included in notions of Southeastern, Southern and Central Europe
Turkey lies partially in Southeastern Europe: only the region known as East Thrace, which constitutes 3% of the country's total land mass, lies west of the Dardanelles, the Sea of Marmara, and the Bosphorus.
Partially recognized states: Kosovo belongs to Southeastern Europe.
Ancient kingdoms of the region included Orontid Armenia Albania, Colchis and Iberia. These kingdoms were either from the start, or later on incorporated into various Iranian empires, including the Achaemenid Persian, Parthian, and Sassanid Persian Empires. Parts of the Balkans and more northern areas were ruled by the Achaemenid Persians as well, including Thrace, Paeonia, Macedon, and most of the Black Sea coastal regions of Romania, Ukraine, and Russia. Owing to the rivalry between Parthian Iran and Rome, and later Byzantium and the Sassanid Persians, the former would invade the region several times, although it was never able to hold the region, unlike the Sassanids who ruled over most of the Caucasus during their entire rule.
The earliest known distinctions between east and west in Europe originate in the history of the Roman Republic. As the Roman domain expanded, a cultural and linguistic division appeared between the mainly Greek-speaking eastern provinces which had formed the highly urbanized Hellenistic civilization. In contrast the western territories largely adopted the Latin language. This cultural and linguistic division was eventually reinforced by the later political east–west division of the Roman Empire. The division between these two spheres was enhanced during Late Antiquity and the Middle Ages by a number of events. The Western Roman Empire collapsed starting the Early Middle Ages. By contrast, the Eastern Roman Empire, mostly known as the Byzantine Empire, managed to survive and even to thrive for another 1,000 years. The rise of the Frankish Empire in the west, and in particular the Great Schism that formally divided Eastern and Western Christianity, enhanced the cultural and religious distinctiveness between Eastern and Western Europe. Much of Eastern Europe was invaded and occupied by the Mongols.
The conquest of the Byzantine Empire, center of the Eastern Orthodox Church, by the Ottoman Empire in the 15th century, and the gradual fragmentation of the Holy Roman Empire (which had replaced the Frankish empire) led to a change of the importance of Roman Catholic/Protestant vs. Eastern Orthodox concept in Europe. Armour points out that the Cyrillic alphabet use is not a strict determinant for Eastern Europe, where from Croatia to Poland and everywhere in between, the Latin alphabet is used. Greece's status as the cradle of Western civilization and an integral part of the Western world in the political, cultural and economic spheres has led to it being nearly always classified as belonging not to Eastern, but to Southern or Western Europe. During the late sixteenth and early seventeenth centuries Eastern Europe enjoyed a relative high standard of living. This period is also called the east-central European golden age of around 1600.
A major result of the First World War was the breakup of the Russian, Austro-Hungarian, and Ottoman empires, as well as partial losses to the German Empire. A surge of ethnic nationalism created a series of new states in Eastern Europe, validated by the Versailles Treaty of 1919. Poland was reconstituted after the partitions of the 1790s had divided it between Germany, Austria, and Russia. New countries included Finland, Estonia, Latvia, Lithuania, Ukraine (which was soon absorbed by the Soviet Union), Czechoslovakia, and Yugoslavia. Austria and Hungary had much reduced boundaries. Romania, Bulgaria and Albania likewise were independent. All the countries were heavily rural, with little industry and only a few urban centers. Nationalism was the dominant force but most of the countries had ethnic or religious minorities who felt threatened by majority elements. Nearly all became democratic in the 1920s, but all of them (except Czechoslovakia and Finland) gave up democracy during the depression years of the 1930s, in favor of autocratic or strong-man or single party states. The new states were unable to form stable military alliances, and one by one were too weak to stand up against Nazi Germany or the Soviet Union, which took them over between 1938 and 1945.
Russia, defeated in the First World War, lost territory as the Baltics and Poland made good their independence. The region was the main battlefield in the Second World War (1939–45), with German and Soviet armies sweeping back and forth, with millions of Jews killed by the Nazis, and millions of others killed by disease, starvation, and military action, or executed after being deemed as politically dangerous. During the final stages of World War II the future of Eastern Europe was decided by the overwhelming power of the Soviet Red Army, as it swept the Germans aside. It did not reach Yugoslavia and Albania however. Finland was free but forced to be neutral in the upcoming Cold War. The region fell to Soviet control and Communist governments were imposed. Yugoslavia and Albania had their own Communist regimes. The Eastern Bloc with the onset of the Cold War in 1947 was mostly behind the Western European countries in economic rebuilding and progress. Winston Churchill, in his famous "Sinews of Peace" address of March 5, 1946 at Westminster College in Fulton, Missouri, stressed the geopolitical impact of the "iron curtain":
From Stettin in the Baltic to Trieste in the Adriatic an iron curtain has descended across the Continent. Behind that line lie all the capitals of the ancient states of Central and Eastern Europe. Warsaw, Berlin, Prague, Vienna, Budapest, Belgrade, Bucharest, and Sofia.
The Soviet secret police, the NKVD, working in collaboration with local communists, created secret police forces using leadership trained in Moscow. As soon as the Red Army had expelled the Germans, this new secret police arrived to arrest political enemies according to prepared lists. The national Communists then took power in a normally gradualist manner, backed by the Soviets in many, but not all, cases. They took control of the Interior Ministries, which controlled the local police. They confiscated and redistributed farmland. Next the Soviets and their agents took control of the mass media, especially radio, as well as the education system. Third the communists seized control of or replaced the organizations of civil society, such as church groups, sports, youth groups, trade unions, farmers organizations, and civic organizations. Finally they engaged in large scale ethnic cleansing, moving ethnic minorities far away, often with high loss of life. After a year or two, the communists took control of private businesses and monitored the media and churches. For a while, cooperative non-Communist parties were tolerated. The communists had a natural reservoir of popularity in that they had destroyed Hitler and the Nazi invaders. Their goal was to guarantee long-term working-class solidarity. Eastern Europe after 1945 usually meant all the European countries liberated and then occupied by the Soviet army. It included the German Democratic Republic (also known as East Germany), formed by the Soviet occupation zone of Germany. All the countries in Eastern Europe adopted communist modes of control. These countries were officially independent from the Soviet Union, but the practical extent of this independence – except in Yugoslavia, Albania, and to some extent Romania – was quite limited. Under pressure from Stalin these nations rejected grants from the American Marshall plan. Instead they participated in the Molotov Plan which later evolved into the Comecon (Council for Mutual Economic Assistance). When NATO was created in 1949, most countries of Eastern Europe became members of the opposing Warsaw Pact, forming a geopolitical concept that became known as the Eastern Bloc.First and foremost was the Soviet Union (which included the modern-day territories of Russia, Lithuania, Latvia, Estonia, Belarus, Ukraine, and Moldova). Other countries dominated by the Soviet Union were the German Democratic Republic, People's Republic of Poland, Czechoslovak Socialist Republic, People's Republic of Hungary, People's Republic of Bulgaria, and Socialist Republic of Romania.
The Socialist Federal Republic of Yugoslavia (SFRY; formed after World War II and before its later dismemberment) was not a member of the Warsaw Pact. It was a founding member of the Non-Aligned Movement, an organization created in an attempt to avoid being assigned to either the NATO or Warsaw Pact blocs. The movement was demonstratively independent from both the Soviet Union and the Western bloc for most of the Cold War period, allowing Yugoslavia and its other members to act as a business and political mediator between the blocs.
The Socialist People's Republic of Albania broke with the Soviet Union in the early 1960s as a result of the Sino-Soviet split, aligning itself instead with China. Albania formally left the Warsaw pact in September 1968 after the suppression of the Prague spring. When China established diplomatic relations with the United States in 1978, Albania also broke away from China. Albania and especially Yugoslavia were not unanimously appended to the Eastern Bloc, as they were neutral for a large part of the Cold War period.
With the fall of the Iron Curtain in 1989, the political landscape of the Eastern Bloc, and indeed the world, changed. In the German reunification, the Federal Republic of Germany peacefully absorbed the German Democratic Republic in 1990. In 1991, COMECON, the Warsaw Pact, and the Soviet Union were dissolved. Many European nations which had been part of the Soviet Union regained their independence (Belarus, Moldova, Ukraine, as well as the Baltic States of Latvia, Lithuania, and Estonia). Czechoslovakia peacefully separated into the Czech Republic and Slovakia in 1993. Many countries of this region joined the European Union, namely Bulgaria, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Romania, and Slovakia.