West Berlin ( or , ) was a political enclave which comprised the western part of Berlin during the years of the Cold War. Although West Berlin was de jure not part of West Germany, lacked any sovereignty, and was under military occupation until German reunification in 1990, the territory was claimed by the Federal Republic of Germany (FRG) which was heavily disputed by the Soviet Union and other Eastern Bloc countries. However, West Berlin de facto aligned itself politically with the FRG on 23 May 1949, was directly or indirectly represented in its federal institutions, and most of its residents were citizens of the FRG. West Berlin was formally controlled by the Western Allies and entirely surrounded by the Soviet-controlled East Berlin and East Germany. West Berlin had great symbolic significance during the Cold War, as it was widely considered by westerners an "island of freedom" and America's most loyal counterpart in Europe. It was heavily subsidised by West Germany as a "showcase of the West". A wealthy city, West Berlin was noted for its distinctly cosmopolitan character, and as a centre of education, research and culture. With about two million inhabitants, West Berlin had the largest population of any city in Germany during the Cold War era. West Berlin was east and north of the Inner German border and only accessible by land from West Germany by narrow rail and highway corridors. It consisted of the American, British, and French occupation sectors established in 1945. The Berlin Wall, built in 1961, physically separated West Berlin from its East Berlin and East German surroundings until it fell in 1989. On 3 October 1990, the day Germany was officially reunified, East and West Berlin formally reunited, joined the Federal Republic as a city-state and, eventually, once again became the capital of Germany. Origins The London Protocol of 1944 and the Potsdam Agreement established the legal framework for the occupation of Germany in the wake of World War II. According to these agreements, Germany would be formally under the administration of four Allies (the United States, the United Kingdom, the Soviet Union, and France) until a German government "acceptable to all parties" could be established. The territory of Germany, as it existed in 1937, would be reduced by most of Eastern Germany thus creating the former eastern territories of Germany. The remaining territory would be divided into four zones, each administered