Italy became a country of mass emigration soon after national reunification in the late 19th century. Between 1898 and 1914, the peak years of Italian diaspora, approximately 750,000 Italians emigrated each year. Italian communities once thrived in the former African colonies of Eritrea (nearly 100,000 at the beginning of World War II), Somalia and Libya (150,000 Italians settled in Libya, constituting about 18% of the total population). All of Libya's Italians were expelled from the North African country in 1970.
In the decade after World War II, up to 350,000 ethnic Italians left Yugoslavia (see Istrian exodus). Large numbers of people with full or significant Italian ancestry are found in Brazil (25 million), Argentina (20 million), United States (17.8 million), France (5 million), Uruguay (1.5 million), Canada (1.4 million), Venezuela (900,000) and Australia (800,000).
At the start of 2010 there were 4,279,000 foreign nationals resident in Italy and registered with the authorities. This amounted to 7.1% of the country's population and represented a year-on-year increase of 388,000. These figures include more than half a million children born in Italy to foreign nationals second generation immigrants are becoming an important element in the demographic picture but exclude foreign nationals who have subsequently acquired Italian nationality; this applied to 53,696 people in 2008. They also exclude illegal immigrants, the so-called clandestini whose numbers are difficult to determine. In May 2008 The Boston Globe quoted an estimate of 670,000 for this group.
Since the expansion of the European Union, the most recent wave of migration has been from surrounding European nations, particularly Eastern Europe, and increasingly Asia, replacing North Africa as the major immigration area. Some 997,000 Romanians, around 10 percent of them being Romanis, are officially registered as living in Italy, replacing Albanians and Moroccans as the largest ethnic minority group.
As of 2009, the foreign born population origin of Italy was subdivided as follows: Europe (53.5%), Africa (22.3%), Asia (15.8%), the Americas (8.1%) and Oceania (0.06%). The distribution of foreign born population is largely uneven in Italy: 87.3% of immigrants live in the northern and central parts of the country (the most economically developed areas), while only 12.8% live in the southern half of the peninsula.
According to Eurostat, in 2010 there were 4.8 million foreign-born residents in Italy, corresponding to 8.0% of the total population. Of these, 3.2 million (5.3%) were born outside the EU and 1.6 million (2.6%) were born in another EU Member State.