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
Central Europe It includes countries of varied sizes, ranging from tiny Liechtenstein to Germany, the largest European country by population (that is entirely placed in Europe). Demographic figures for countries entirely located within notion of Central Europe ("the core countries") number around 165 million people, out of which around 83 million are residents of Germany. Other populations include: Poland with around 38.5 million residents, Czech Republic at 10.5 million, Hungary at 10 million, Austria with 8.9 million, Switzerland with its 8.5 million inhabitants, Slovakia at 5.4 million, Croatia with its 4.3 million residents, Slovenia at 2 million (2014 estimate) and Liechtenstein at