West Berlin was a political exclave that existed between 1949 and 1990. It comprised the western regions of Berlin, which were bordered by East Berlin and parts of East Germany. West Berlin consisted of the American, British, and French occupation sectors, which had been established in 1945. It was politically closely affiliated with West Germany, although it had a special status, because its administration was formally conducted by the Western Allies. East Berlin encompassed the region occupied and administered by the Soviet Union, and was claimed as capital by East Germany. The Western Allies did not recognise this claim, as they asserted that the entire city of Berlin was legally under four-power administration. The Berlin Wall, built in 1961, physically divided East and West Berlin until it fell in 1989.

With about two million inhabitants, West Berlin had the highest number of residents of any city in Cold War-era Germany.

Berlin ( /bɜrˈlɪn/; German pronunciation: [bɛɐ̯ˈliːn] ( listen)) is the capital city of Germany and one of the 16 states of Germany. With a population of 3.5 million people, Berlin is Germany's largest city and is the second most populous city proper and the eighth most populous urban area in the European Union. Located in northeastern Germany, it is the center of the Berlin-Brandenburg Metropolitan Region, which has 5.9 million residents from over 190 nations. Located in the European Plains, Berlin is influenced by a temperate seasonal climate. Around one third of the city's area is composed of forests, parks, gardens, rivers and lakes.

First documented in the 13th century, Berlin was the capital of the Kingdom of Prussia (1701–1918), the German Empire (1871–1918), the Weimar Republic (1919–1933) and the Third Reich (1933–1945).Berlin in the 1920s was the third largest municipality in the world. After World War II, the city became divided into East Berlin—the capital of East Germany—and West Berlin, a West German exclave surrounded by the Berlin Wall (1961–1989). Following German reunification in 1990, the city regained its status as the capital of Germany, hosting 147 foreign embassies.