The border of the city of Milano was decided 200 years ago, when the city had only 400.000 inhabitants. Today inside the same borders there are 1.300.000 inhabitants, but the REAL CITY is bigger, and has a population on 4.500.000 of inhabitants. That’s people live in Milan and in other 40/50 municipalities that are called the First and the Second Ring, or also the Grande Milan (the Big Milan). That’s the CITY of Milan.
then, as in all the rest of the world there is the Metropolitan Area of Milan, that is not exactly definite and can have from 6.5 Millions if you calculate it with the German, Spanish and English way of the Metropolitan Areas, or more than 7.5/8 Millions if you calculate it with the French and American way for M.A. Milan is the 3° biggest city of Western Europe after London and Paris.
I'm Italian and maybe I can help you as regards the City of Milan... In my opinion we can consider the metropolitan area as a groups of 40/50 municipalities in the province of Milan (let's say Rohm, Sesto San Giovanni and so on...). In the article there is a list of footballers born in this Metropolitan Area... so I can understand that also Bergamo, Varese and all the major city of Lombardia are included. In my opinion it's too much!
Maybe the list is not really correct: for example Paolo Rossi was born in Prato, near Florence; Franco and Giuseppe Baresi were born in Travagliato, a countrytown in the province of Brescia (more or less 50 miles from Milan...) and so on!
Photo: sxc.hu