Europe of population are Saint Petersburg, Madrid, Berlin and Rome, each having over 3 million residents. When considering the commuter belts or metropolitan areas, within the EU (for which comparable data is available) London covers the largest population, followed in order by Paris, Madrid, Barcelona, Berlin, the Ruhr area, Rome, Milan, Athens and Warsaw. "Europe" as a cultural concept is substantially derived from the shared heritage of the Roman Empire and its culture. The boundaries of Europe were historically understood as those of Christendom (or more specifically Latin Christendom), as established or defended throughout the medieval and early modern history of
Ethnic groups in Europe European Union, accounting for 72% of the EU's population. Islam has some tradition in the Balkans and the Caucasus due to conquest and colonization from the Ottoman Empire in the 16th to 19th centuries. Muslims account for the majority of the populations in Albania, Azerbaijan, Kosovo, Northern Cyprus (controlled by Turks), and Bosnia and Herzegovina. Significant minorities are present in the rest of Europe. Russia also has one of the largest Muslim communities in Europe, including the Tatars of the Middle Volga and multiple groups in the Caucasus, including Chechens, Avars, Ingush and others. With 20th-century migrations, Muslims in Western