As of March 2010, the city-state of Berlin had a population of 3,440,441 registered inhabitants in an area of 891.82 square kilometers (344.33 sq mi). The city's population density was 3,848 inhabitants per km² (9,966/sq mi). The urban area of Berlin stretches beyond the city limits and comprises about 3.7 million people, while the metropolitan area of the Berlin-Brandenburg region is home to about 4.3 million in an area of 5,370 km2 (2,070 sq mi). In 2004, The Larger Urban Zone was home to over 4.9 million people in an area of 17,385 km².
National and international migration into the city has a long history. In 1685, following the revocation of the Edict of Nantes in France, the city responded with the Edict of Potsdam, which guaranteed religious freedom and tax-free status to French Huguenot refugees for ten years. The Greater Berlin Act in 1920 incorporated many suburbs and surrounding cities of Berlin. It formed most of the territory that comprises modern Berlin. The act increased the area of Berlin from 66 km2 (25 sq mi) to 883 km2 (341 sq mi) and the population from 1.9 million to 4 million.
Active immigration and asylum politics in West Berlin triggered waves of immigration in the 1960s and 1970s. Currently, Berlin is home to about 250,000 Turks (especially in Kreuzberg, Neukölln and Wedding, a locality in the borough of Mitte), making it the largest Turkish community outside of Turkey.
In the 1990s the Aussiedlergesetze enabled immigration to Germany of some residents from the former Soviet Union. Today ethnic Germans from countries of the former Soviet Union make up the largest portion of the Russian-speaking community. The current decade experiences an increasing influx from various Western countries. Especially young EU-Europeans are settling in the city. Additionally, Berlin has seen a rise of African immigrants during the last two decades.
In December 2010, 457,806 residents (13.5% of the population) were of foreign nationality, originating from 190 different countries. The largest groups of foreign nationals are those from Turkey (104,556), Poland (40,988), Serbia (19,230), Italy (15,842), Russia (15,332), France (13,262), Vietnam (13,199), the United States (12,733), Bosnia and Herzegovina (10,198), the United Kingdom (10,191), Croatia (10,104), and Israel (estimated 10,000). An estimated 394,000 citizens (12.2%) are descendants of international migrants and have either become naturalized German citizens or obtained citizenship by virtue of birth in Germany. All in all, about 25%–30% of the population is of foreign origin
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