Europe is a continent that comprises the westernmost peninsula of Eurasia. It is generally divided from Asia by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting the Black and Aegean Seas.
Europe is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and the Black Sea and its connected waterways to the southeast. Yet the borders of Europe—a concept dating back to classical antiquity—are arbitrary, as the primarily physiographic term "continent" also incorporates cultural and political elements.
The culture of Europe can be described as a series of overlapping cultures; cultural mixes exist across the continent. There are cultural innovations and movements, sometimes at odds with each other. Thus the question of "common culture" or "common values" is complex.
According to historian Hilaire Belloc, for several centuries the peoples of Europe based their self-identification on the remaining traces of the Roman culture and on the concept of Christendom, because many European-wide military alliances were of religious nature: the Crusades (1095–1291), the Reconquista (711–1492), the Battle of Lepanto (1571)