Berlin, a city and state in Germany. (The city and state have the same boundaries.) Berlin is the nation's capital and largest city. After Berlin's capture by Soviet forces in 1945, during World War II, the city was divided into four sectors. The eastern sector was governed by the Soviet Union and each of the remaining sectors by one of the other major Allied powers—the United States, Great Britain, and France. During 1948–49, Berlin was divided into two parts—East Berlin and West Berlin.

In 1949, East Berlin was made the capital of East Germany. Though it was 100 miles (160 km) east of the border with the Federal Republic of Germany (West Germany), West Berlin was economically and culturally integrated into the Federal Republic. Technically, West Berlin was governed by the Western powers until 1990. In October, 1990, East and West Berlin, along with the rest of Germany, were reunited and Berlin again became the capital of Germany.

Berlin is situated on a low-lying plain on the banks of the Spree River and has an area of 341 square miles (883 km 2 ). The Spree flows from southeastern Berlin to the western part of the city, where it joins the Havel River, a tributary of the Elbe. A system of canals crosses Berlin. Numerous lakes dot the area, including the Grosser Wannsee, the Tegeler See, and the Grosser Müggelsee.

Before its division, Berlin was Germany's premier city. It was not only the seat of political power, but also a vibrant center of the arts, education, commerce, and industry. When Berlin was divided, the two cities functioned almost independently of one another. Both were major manufacturing and commercial centers; both had prominent educational institutions and cultural attractions. After reunification in 1990, Berlin once again became Germany's premier city.