Western Europe is the western region of Europe. The region's countries and territories vary depending on context.
Beginning with foreign exploration during the Age of Discovery, roughly from the 15th century, the concept of Europe as "the West" gradually became distinguished from and eventually replaced the dominant use of "Christendom" as the preferred endonym within the region. Later, during the Age of Enlightenment, the concept of "Eastern Europe" was created to juxtapose that of "Western Europe".[