West Berlin
West Berlin was the name given to the western part of Berlin between 1948 and 1990 (in 1948 forcibly split into West Berlin and East Berlin during the Soviet Berlin Blockade). It consisted of the American, British, and French occupation sectors established in 1945. It was in many ways integrated with, although legally not a part of, West Germany. The Soviet sector became East Berlin, which the GDR claimed as its capital, though the Western Allies did not recognise this claim, as they asserted that the whole city was legally under four-power occupation. The building of the Berlin Wall in 1961 sealed the border to West Berlin, which since the end of the Second World War had been surrounded by communist East Berlin and East Germany.
With around two million inhabitants, West Berlin, until the partial reunification of Germany in 1990, was the most populated city of Cold War-era Germany, although it did not officially belong to either of the two German states.