Western Europe at its most general meaning means 'all the countries in the West of Europe'. The concept at different times has had different meanings, at times including political and cultural considerations as well as geographical. Since the end of WWII, the term is commonly used to describe the affluent, mixed-capitalist democracies, allied with the United States.

Classical antiquity and medieval origins

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 Byzantine Empire, managed to survive and even to thrive for another 1000 years. The rise of the Frankish Empire in the west, and in particular the Great Schism that formally divided Eastern Orthodoxy and Roman Catholicism, enhanced the cultural and religious distinctiveness between Eastern and Western Europe.

The conquest of the Byzantine Empire, center of the Eastern Orthodox Church, by the Muslim 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.

Historical events like the Renaissance, the Protestant Reformation by Martin Luther and the Counter-Reformation of the Catholic Church, the Age of Enlightenment, the French Revolution, and the Industrial Revolution are considered to be common experiences which have shaped Western European culture and identity. During the Age of Discovery, most of the Western European countries colonized Africa, Asia, South and North America. All these historical events and cultural developments have influence over the Western European concept.

The Cold War

During the final stages of WWII the future of Europe was decided between the Allies in the 1945 Yalta Conference, between the Prime Minister of the United Kingdom, Winston Churchill, the President of the United States, Franklin Delano Roosevelt, and the Premier of the Soviet Union, Joseph Stalin.

Post-war Europe would be divided into two major spheres: the "West", influenced by the United States, and the Eastern Bloc, dominated by the Soviet Union. With the onset of the Cold War, Europe was divided by the Iron Curtain.

This term had been used during World War II by German Propaganda Minister Joseph Goebbels and later Count Lutz Schwerin von Krosigk in the last days of the war; however, its use was hugely popularised by Winston Churchill, who used it in his famous "Sinews of Peace" address March 5, 1946 at Westminster College in Fulton, Missouri:

Although some countries were officially neutral, they were classified according to the nature of their political and economical systems. This division largely defined the popular perception and understanding of Western Europe and its borders with Eastern Europe till this day.