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
Coal in Europe Coal from fields differ in ash and moisture content, energy value, volatile elements, sulphur content, and other properties. Anthracite and bituminous coal are relatively high value compared to lignite and peat, which have lower energy and higher moisture contents. Coal is often used in the iron and steel industry, or to produce energy. Russia (365 Mt), Germany (176 Mt) and Poland (131 Mt) are the largest producers of coal in Europe as of 2016. Largest net importer was Germany with 53 Mt, and the largest net exporter was Russia with 147 Mt. Largest electricity production from coal in 2016 were