After World War II, at the Potsdam conference it was decided that what remained of Nazi territory was to be split into 4 zones, each one controlled by one of the wartime Allies - America, Britain, Russia and France. The capital, Berlin was also divided similarly, even though it was actually in Soviet territory. In a speech in 1946, Winston Churchill said that there was “an iron cutrain descending across Europe” - the predicted a further divide between Capitalism and Communism. 

This divide was increased and formalised by the Berlin Blockade in June 1948, when the Soviet forces closed entry to Berlin from the west in an attempt to prevent the Allies unifying the western part of Germany. The British and US forces resonded by sending supplies to the city by air for over a year (the Berlin Airlift). The blockade was lifted in May 1949, although the intention was for the four countries to rule together, the growing tension forced France, Britain and America to combine their territories to create the Federal Republic of Germany and West Berlin, while the Soviets formed the German Democratic Republic, which encompassed East Berlin. It marked the formal division of the city.  

Germany - 1945                                        Germany - 1949

Churchill’s words had been prophetic as three years later, the Republics had been formed and the gulf between the east and west was established.

By 1961, the divide was well established. The west had prospered, while the east, though not poor by Communist standards, was still well behind the west. Because of this, many skilled and east Germans were moving to the west. This meant that the economy of the Democratic Republic was under threat. Also, the Soviets were afraid of the west interfering with their rule in Eastern Germany. They needed a solution. From 13th August 1961, the East German security forces sealed off all but 12 of the 80 crossing points to West Berlin with a barbed wire barrier. It was reinforced with concrete by the Russians. To prevent the escape of unwilling inhabitants of East Berlin to the rival political and economic system of West Berlin the interconnecting link between the two sides was ‘Checkpoint Charlie’. The wall was a physical manifestation of Churchill’s ‘Iron Curtain’.

Though not creating any problems for the Politicians who had ordered its construction, the wall caused a great deal of trouble for the people of Berlin. Families were split up with no way of having access to each other, people working on the other side of the city to which they lived lost their jobs and people who tried to cross the border were shot. This caused many demonstrations in West Berlin and when the USA failed to respond, the Berliners lost faith in government.

 In 1989, Hungary opened its borders to Western Europe. This meant that for the first time since 1961, East Berliners could gain access to West Berlin via Hungary. Also, the East Berliners began to stage protests which forced the government to make reforms. The first major step happened on the 9th November 1989, when the head of the Communist Party in East Berlin announced that the borderwould be opened for private trips. The news spread and soon people were gathering and protesting on both sides of the wall. Soon people began tearing down the wall that had divided them. This began a large scale emmigration of people out of East Berlin and soon checkpoints were opened for pedestrians. Parties broke out and on 1st July 1990, East and West Germany were reunited. All travel restrictions were dropped and the Iron Curtain had been destroyed.

Construction of the Wall                                     The Wall In 1989

Useful Links:

http://en.wikipedia.org/wiki/Berlin_Wall - The Berlin Wall On Wikipedia

http://www.berlinermauer.se/BerlinWall/ - The Official Berlin Wall Site

http://www.bbc.co.uk/worldservice/people/highlights/010815_berlinwall.shtml - The Berlin Wall On The BBC