<Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> West Berlin was a political enclave which comprised the western part of Berlin during the years of the Cold War . There was no specific date on which the sectors of Berlin occupied by the Western Allies became "West Berlin", but 1949 is a widely accepted date . West Berlin was formally controlled by the Western Allies and formed a de facto part of West Germany, even though it was 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 as an "island of freedom". It was heavily subsidised by West Germany as a "showcase of the West". A wealthy city, West Berlin was noted for its distinctly liberal and cosmopolitan character, and as a centre of education, research and culture . With about two million inhabitants, West Berlin had the biggest population of any city in Germany during the Cold War era . </P> <P> West Berlin was 100 miles (161 kilometres) 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 . It was, however, a de facto part of West Germany . It had a special and unique legal status because its administration was formally conducted by the Western Allies . At the same time, East Berlin, de jure occupied and administered by the Soviet Union, was the de facto capital of East Germany . The Berlin Wall, built in 1961, physically separated West Berlin from its East Berlin and East German surroundings until it fell in 1989 . </P> <P> The Potsdam Agreement established the legal framework for the occupation of Germany in the wake of World War II . According to this agreement, Germany would be formally under the administration of the four major wartime Allies (the United States, the United Kingdom, France, and the Soviet Union) 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 by one of the four allied countries . Berlin, which was surrounded by the Soviet zone of occupation--newly established in most of Middle Germany--would be similarly divided, with the Western Allies occupying an enclave consisting of the western parts of the city . According to the agreement, the occupation of Berlin could end only as a result of a quadripartite agreement . The Western Allies were guaranteed three air corridors to their sectors of Berlin, and the Soviets also informally allowed road and rail access between West Berlin and the western parts of Germany (see section on traffic). </P>

When the soviet union sealed off the city of berlin