Milan is the second-largest city in Italy, the capital city of the region of Lombardy and of the province of Milan. The city proper has a population of about 1.3 million, while its urban area, roughly coinciding with its administrative province and the bordering Province of Monza and Brianza (created in 2004 splitting the northern part from the province of Milan itself), is one of Europe's largest with an estimated population of over 4 million spread over 1,980 km2 (764.48 sq mi), with a consequent population density of more than 2,000 inhabitants/km². The growth of many suburbs and satellite settlements around the city proper following the great economic boom of the 1950-60s and massive commuting flows suggest that socioeconomic linkages have expanded well beyond the boundaries of the city proper and its agglomeration, creating a metropolitan area of 7.4 million population expanded all over the central section of Lombardy region. It has been suggested that the Milan metropolitan area is part of the so-called Blue Banana, the area of Europe with the highest population and industrial density.

The city was founded by the Insubres, a Celtic people. Milan was later captured by the Romans in 222 BC, and later was the capital city of the Western Roman Empire from 286 until 402 AD. Milan became one of the most prosperous Italian cities during the High Middle Ages, playing a primary role in the Lombard League. Later Milan became the capital city of the Duchy of Milan, being ruled by the Visconti, the Sforza, the Spanish and the Austrians. In 1796, Milan was conquered by the French troops of Napoleon I, who made it the capital of the puppet state of the Kingdom of Italy in 1805.[6][7] Later Milan became the capital city of the Kingdom of Lombardy–Venetia, which was part of the Austrian Empire. In 1859 the city was unified with the Kingdom of Sardinia, which later became the Kingdom of Italy. During the Romantic period, Milan was a major cultural centre in Europe, attracting several artists, composers and important literary figures. Later, during World War II, the city was badly affected by Allied bombings, and after German occupation in 1943, Milan became the main hub of the Italian resistance. Despite this, Milan saw a post-war economic growth, attracting thousands of immigrants from Southern Italy and abroad.

Over the years, Milan has had an increase in the number of international inhabitants, and 15.2% of Milan's population is foreign born. The city remains one of Europe's main transportation and industrial hubs, and Milan is the EU's 10th most important centre for business and finance (2009) with its economy being the world's 26th richest by purchasing power.

The Milan metropolitan area has Europe's 7th largest GDP in 2008. The province of Milan (which increasingly is becoming a single administrative urban unit to supersede the limited commune) had a GDP pp per capita of around €40,000 in 2007 (161% of the EU 27 average) which was the highest of any Italian province (Il Sole 24 Ore Quality of life survey 2008) and the city's workers have the highest average income rates in Italy, and 26th in the world. In addition, Milan is the world's 11th most expensive city for expatriate employees, and according to a 2010 study by the Economist Intelligence Unit, the city is the world's 12th most expensive to live in. Its economic environment has made it, according to several studies, the world's 20th and Europe's 10th top business and financial centre, having been highly successful in terms of city branding.
Milan is recognised as a world fashion and design capital, with a major influence in commerce, industry, music, sport, literature, art and media; it has thus been ranked by GaWC as an Alpha+ world city in 2008. The Lombard metropolis is especially famous for its fashion houses and shops (such as along Via Monte Napoleone) and the Galleria Vittorio Emanuele in the Piazza Duomo (reputed to be the world's oldest shopping mall). The city has an ancient cultural heritage and legacy, vibrant nightlife, and is home to numerous famous dishes, such as the Panettone Christmas cake and the risotto alla Milanese. The city has a particularly famous musical, particularly operatic, tradition, being the home of several important composers (such as Giuseppe Verdi) and theatres (such as the Teatro alla Scala). Milan is also well known for containing several important museums, universities, academies, palaces, churches and libraries (such as the Academy of Brera and the Castello Sforzesco) and two renowned football teams: A.C. Milan and F.C. Internazionale Milano. Euromonitor International ranked Milan as the world's 63rd most visited city in 2009, with 1.894 million arrivals. The city hosted the 1906 World Exposition and will host the 2015 Universal Exposition.

Inhabitants of Milan are referred to as "Milanese" (Italian: Milanesi or informally Meneghini or Ambrosiani). Milan, for its pivotal economic role and its fervent political and cultural activity that often anticipates national trends, it is often nicknamed as the "moral capital of Italy".

In its political history, Milan was governed for more than 45 years by the Italian Socialist Party in coalition with Christian Democracy and Italian Democratic Socialist Party. However since 1993 it has become a stronghold of the center-right coalition lead by Silvio Berlusconi: in 2006 and in 2008 Berlusconi's coalition received more than 52,6% and 49,1% of the votes.

The most important political institution in Milan is the City Council, which is composed by 48 members elected every five years.
The current mayor of Milan is Giuliano Pisapia, representing a centre-left coalition composed by Democratic Party, Left Ecology Freedom, Greens and Communist Refoundation Party. He was elected in May 2011, defeating the incumbent mayor Letizia Moratti (PdL) and becoming the first elected-mayor from a left-wing party.

The city of Milan is subdivided into administrative zones, called Zone. Before 1999, the city had 20 Zone; in 1999 the administration decided to reduce the number of these zones from 20 to 9.
Today, the Zona 1 is in the "historic centre", the zone within the perimeter of the Spanish-era city walls; the other eight cover the areas from the Zona 1 borders to the city limits. So a zone is very big (considering inhabitants' number), comparable to many Italian city or even a half or third of some Italian province (provincia).
Nevertheless a zone's government and zone representatives in Milan have very little power and very few duties.
All zones have an elected president and a council: since 2011 all zones are governed by the center-left.

Despite the fact that Milan has a very small amount of green space in comparison to other cities of the same size, the city does boast a wide variety of parks and gardens. The first public parks were established 1857 and 1862, and were designed by Giuseppe Balzaretto. They were situated in a "green park district", found in the areas of Piazzale Oberdan (Porta Venezia), Corso Venezia, Via Palestro and Via Manin. Most of them were landscaped in a Neoclassical style and represented traditional English gardens, often full of botanic richness. Since 1990 Milan is surrounded by the regional Parco Agricolo Sud Milano that wraps the southern half of the city, connecting Ticino Park in the west and Adda Park in the east. The Park was instituted in order to safeguard and enhance the old agricultural landscape and activities, woodlands and natural reserves, with an overall size of 47,000 hectares.

The most important parks in Milan are the set of adjacent parks in the western area of the city forming Parco Agricolo Sud Milano (Parco delle Cave, 131 hectares; Boscoincittà, 110 hectares; and Trenno Park, 59 hectares, whose total area amounts to about 300 hectares), Sempione Park, Parco Forlanini, Giardini Pubblici, Giardino della Villa Comunale, Giardini della Guastalla and Lambro Park. Sempione Park is a large public park, situated between the Castello Sforzesco and the Peace Arch, near Piazza Sempione. It was built by Emilio Alemagna, and contains a Napoleonic Arena, the Milan City Aquarium, a tower, an art exhibition centre, some ponds and a library. Then there is Parco Forlani, which, with a size of 235 hectares is the largest park in Milan, and contains a hill and a pond. Giardini Pubblici is among Milan's oldest remaining public parks, founded on 29 November 1783, and completed around 1790. It is landscaped in English style, containing a pond, a Natural History Museum of Milan and the Neoclassical Villa Reale. Giardini della Guastalla is also one of the oldest gardens in Milan, and consists mainly of a decorated fish pond.

Milan also hosts three important botanical gardens: the Milan University Experimental Botanical Garden (a small botanical garden operated by the Istituto di Scienze Botaniche), the Brera Botanical Garden (another botanical garden, founded in 1774 by Fulgenzio Witman, an abbot under the orders of Empress Maria Theresa of Austria, and restored in 1998 after several years of abandonment) and the Cascina Rosa Botanical Garden. On January 23, 2003 a Garden of the Righteous was established in Monte Stella to commemorate those who opposed genocides and crimes against humankind. It hosts trees dedicated to Moshe Bejski, Andrei Sakharov, the founders of the Gardens of the Righteous in Yerevan and Pietro Kuciukian, and others. The decision to commemorate a "Righteous" person in this Garden is made every year by a commission of high-profile characters.