This division dominated Europe for centuries, in opposition to the rather short lived Cold War division of 4 decades.
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.
In some media, "Central Europe" can thus partially overlap with "Eastern Europe" of the Cold War Era.
The following countries are labeled Central European by some commentators, though others still consider them to be Eastern European. In some media, "Southeast Europe" can thus partially overlap with "Eastern Europe" of the Cold War Era.
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.
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 schism is the break of communion and theology between what are now the Eastern (Orthodox) and Western (Roman Catholic from the 11th century, as well as from the 16th century also Protestant) churches.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.Another definition was created during the Cold War and used more or less synonymously with the term Eastern Bloc.A similar definition names the formerly communist European states outside the Soviet Union as Eastern Europe.(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 the languages of candidate countries (Albanian, Macedonian and Serbian).Of these, those in italics are classified as "Eastern Europe" in this source, similar to the Cold War division of Europe.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.The Caucasus nations of Armenia, Azerbaijan, and Georgia are included in definitions or histories of Eastern Europe.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 most prominement being that Greece's history for the most part was more so influenced by Mediterranean cultures and contact.