Europe was first divided into east and west during the time of the Roman Republic. As the dominion of Rome began to expand, it became apparent that there were differences in language and culture between the people in the eastern provinces and those of the western territories. The eastern provinces were populated in the main by those who spoke Greek and had adopted the Hellenistic lifestyle. The western territories were populated by those who spoke Latin.
The division of east and west was further expanded during the Roman Empire, late antiquity and the Middle Ages through a series of events. During the early Middle Ages, the Western Roman Empire began to collapse. The Eastern Roman Empire, also known as the Byzantine Empire, remained strong for a further thousand years. As the Frankish Empire rose in the west, what came to be known as the Great Schism, brought about a formal division between Western (Roman Catholic and Protestant) and Eastern Christianity, further distinguishing Western Europe from its Eastern counterpart. A large swath of Eastern Europe was invaded by and subsequently occupied by the Mongols.
Some historians have debated whether Eastern Europe can be construed as a component of the "real" Europe. On the one hand, there is the history of the Eastern Slavs. Part of their history is certainly European. However, it is important to distinguish the impact of Asia on this region and to identify this as a foreign element. Experts have stated that understanding and identifying the nature of Eastern Europe becomes easier once one gains an understanding of, and a working definition for, what constitutes Western Europe. In this context, it becomes easier to understand how the nations of Russia gained significance as an extension of Europe.
The Ottoman Empire conquered Byzantium in the 15th century. The Ottomans were Muslim, which fact led to the splintering of the Holy Roman Empire and a loss of significance in the religious differences between the various Christian denominations in Europe. The division between the Roman Catholics and Protestants and the Eastern Orthodox Church became moot. Still, cultural and linguistic differences remained, and even today many experts define Eastern Europe as that part of Europe in which the two variations of the Cyrillic alphabet are in use.
Near the end of World War II, Europe's future was discussed by the Allies at the 1945 Yalta Conference. Prime Minister Winston Churchill (United Kingdom), President Franklin Delano Roosevelt (United States) and Premier Joseph Stalin (Soviet Union) presided over these discussions. Postwar Europe would be divided into two main areas: the Western Bloc, which was largely capitalist, and the Eastern Bloc, which was, for the most part, communist. As the Cold War set in, the iron curtain effectively divided Europe into two halves and marginalized the concept of Central Europe altogether. The iron curtain was a de facto separation of Warsaw Pact member states from North Atlantic Treaty Organization (NATO) member states and the Nonaligned Movement or neutral states.
The term Iron Curtain was first used during World War II by Joseph Goebbels, the German Propaganda Minister. During the final days of that war, Count Lutz Schwerin von Krosigk also used the term. However, the term was only popularized from on March 5, 1946, when Winston Churchill used it in a speech that was to become famous, the "Sinews of Peace" address. This speech was made in Fulton, Missouri at Westminster College. Churchill said, "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."
Eastern Europe was then comprised of European countries that had been liberated and occupied by the Soviet army. This part of Europe included East Germany. All of the countries in Eastern Europe were ruled by communist governments.
The landscape of Europe once again changed with the fall of the iron curtain in 1989. East and West Germany merged; the Soviet Union was no more, and many of the nations that had been under Soviet Union rule regained their independence. Many former members of the Warsaw Pact joined NATO. Yugoslavia split into several independent nations in 1992 and Czechoslovakia became two nations, the Czech Republic and Slovakia, in 1993.
In 2011, many of the nations once belonging to the Eastern Bloc are now part of the European Union. These states include Bulgaria, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Romania, Slovakia and Slovenia. Other Eastern Bloc states were negotiating EU membership as of 2011, including Croatia, Macedonia and Montenegro.