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
Islam in Europe Muslim population in Europe. Estimates of the percentage of Muslims in Russia (the biggest group of Muslims in Europe) vary from 5 to 11.7%, depending on sources. It also depends on if only observant Muslims or all people of Muslim descent are counted. 58.8% of Albania adheres to Islam, making it the largest religion in the country. The majority of Albanian Muslims are Secular Sunni with a significant Bektashi Shia minority. The percentage is 93.5% in Kosovo, 39.3% in Macedonia (according to the 2002 Census, 46.5% of the children aged 0–4 were Muslim in Macedonia) and 50.7% in Bosnia and