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
Mexico City Salvador, Haiti and Honduras); from Europe (mainly from Spain, Germany and Switzerland, but also from Czech Republic, Hungary, France, Italy, Ireland, the Netherlands, Poland and Romania), from the Middle East (mainly from Egypt, Lebanon and Syria); and recently from Asia-Pacific (mainly from China and South Korea). Historically since the era of New Spain, many Filipinos settled in the city and have become integrated in Mexican society. While no official figures have been reported, population estimates of each of these communities are quite significant. Mexico City is home to the largest population of U.S. Americans living outside the United States. Current