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
Itinerant groups in Europe Itinerant groups in Europe Traveller peoples in Europe and the British Isles, including both Indigenous Travellers and Romani people. There are a number of traditionally itinerant or travelling groups in Europe who are known as "travellers" or "gypsies". The largest of these groups are the Romani people, of Indian origin, who entered Europe in the 14th–15th century; this includes the Sinti people, who are themselves the second largest group. The third largest group in Europe is the Yenish, an indigenous Germanic group. The origins of the indigenous itinerant groups are unclear. They have been assumed to have taken up the