After the end of World War II in Europe, what remained of pre-war Germany west of the Oder-Neisse line was divided into four occupation zones (per the Potsdam Agreement), each one controlled by one of the four occupying Allied powers: the United States, the United Kingdom, France and the Soviet Union.

A map of Germany with the flags denoting which area was administered by which country.
Berlin was bang in the centre of the Soviet zone.

The capital of Berlin, as the seat of the Allied Control Council, was also subdivided into four sectors despite the city’s location fully within the Soviet zone.

Air passages were provided by the Soviets to the Allies.

Within two years, political divisions increased between the Soviets and the other occupying powers. Stalin had revealed to German communist leaders as early as 1945,that he expected to slowly undermine the British position within the British occupation zone, that the United States would withdraw within a year or two, and that nothing then would stand in the way of a united communist Germany within the bloc.
And on 7 October 1949 The German Democratic Republic (East Germany) was declared .However, by a secret treaty, the Soviet Ministry of Foreign Affairs accorded the East German state administrative authority, but not autonomy.

There was a massive difference between the quality of life and opportunities in West Germany (Federal Republic of Germany), which developed into a Western capitalist country with a social market economy and a democratic parliamentary government. GDR or East Germany in contrast was a socialist state under Soviet control.
Very soon there was a massive immigration of East Germans into West Germany who took advantage of the zonal border between occupied zones in Germany.

Murals on an East German govt building ( still existing) showing glowing faces and happy workers . Whereas reality was discontent

The inner German border was officially sealed in 1952,but the border in Berlin was still considerably more accessible because it was administered by all four occupying powers and so Berlin became the main route for defection by East Germans to the West.
On Saturday, 12 August 1961, an order was signed by east german govt to close the border and erect a wall.
Overnight a barbed wire fence appeared. At midnight, the police and units of the East German army began to close the border and, by Sunday morning, 13 August, the border with West Berlin was closed. East German troops and workers had begun to tear up streets running alongside the border to make them impassable to most vehicles and to install barbed wire entanglements and fences along the 156 kilometres (97 mi) around the three western sectors, and the 43 kilometres (27 mi) that divided West and East Berlin

Overnight a people were divided.
Billy Wilder was shooting in Berlin the morning the Wall went up, and the crew had to move to Munich. When the movie opened that December, the writer-director appended this preface: “On Sunday, August 13th, 1961, the eyes of America were on the nation’s capital, where Roger Maris was hitting home runs #44 and 45 against the Senators. On that same day, without any warning, the East German Communists sealed off the border between East and West Berlin. I only mention this to show the kind of people we’re dealing with — REAL SHIFTY.”

On 15 August 1961, Conrad Schumann was guarding the construction of the Berlin Wall at Ruppiner Straße At that time, the wall was only a low barbed wire fence. From the other side, West Germans shouted to him, “Komm’ rüber!” (“Come over!”), and a police car pulled up to wait for him. Schumann jumped over the barbed wire fence and was promptly driven away from the scene by the West Berlin police. West German photographer Peter Leibing photographed Schumann’s escape, and this picture has since become an iconic image of the Cold War era.
This is a painting on a column in Berlin.

Over the years there were many attempts at escape . They are documented in the Museum of Topography or Terrors,
The most heart rending is of 18 year old east German brick – layer , Peter Fechter who became one of the first victims of the Berlin Wall’s border guards while trying to cross over to what was then West Berlin.
After he was shot down he lay bleeding and crying for help in full view of both East and west German guards and yet no help was given.

Demonstrations after the death of Peter Fecter

Border at Checkpoint Charlie marked by bricks

The fall of the Berlin Wall

It’s always the small people who change things. It’s never the politicians or the big guys. I mean, who pulled down the Berlin wall? It was all the people in the streets. The specialists didn’t have a clue the day before.
Luc Besson

November 9, 1989 saw a new travel law when after the dramatic events such as a massive flight of inhabitants of the GDR via Hungary and big demonstrations in Leipzig on Mondays and after much discussion , the leader of East Berlin’s communist party , Günter Schabowski, said at about 7 p.m. in somewhat unclear words that the border would be opened for “private trips abroad”. Little later, an onrush of East Berliner’s towards West Berlin began, and there were celebrations at the Brandenburg Gate and at the Kurfürstendamm in West Berlin. On November 10, demolition works began with the aim of creating new border crossings. On November 12, a checkpoint at the Potsdamer Platz was opened, and on December 22, a checkpoint for pedestrians was opened at the Brandenburg Gate. So-called “wall woodpeckers” hammered pieces out of the wall, many of which were sold as souvenirs. A few larger segments were officially donated or sold.
On July 1 1990, an economic, monetary and social union between East and West Germany was formed, and all restrictions concerning travels were dropped. The wall had vanished almost completely by 1991; there are a few remainders at the Bernauer Strasse, the Niederkirchnerstrasse (near the building of the former Prussian parliament, now housing the parliament of Berlin) and as the 1.3 km long “East-Side-Gallery” near the railway station “Ostbahnhof”.

The Eastside gallery

On February 1997, a red line was painted on the pavement at the former “Checkpoint Charlie” to mark the course of the former Berlin wall. This line shall reach a length of 20 km and shall be replaced by two rows of paving stones.

Checkpoint Charlie

Checkpoint Charlie (alpha,bravo,charlie) was the name given by the Western Allies to the best-known Berlin Wall crossing point between East Berlin and West Berlin during the Cold War.
Checkpoint Charlie became a symbol of the Cold War, representing the separation of east and west.

A chilling reminder to those who went into East berlin…..

Museum at Checkpoint Charlie was created to document the so-called “best border security system in the world” (in the words of East German general Heinz Hoffmann). On display are the photos and related documents of successful escape attempts from East Germany, together with the escape apparatus: hot-air balloons, getaway cars, chairlifts, and a mini-U-Boat.

The checkpoint’s gate has been replaced by larger-than-life posters of a young American soldier facing east and a young Russian soldier facing west.

The rebuilt guard station now hosts two actors playing American guards who pose for photos.They charge 2 euros for it and 5 for a stamp. They even greet you in your language. We played guessing games. Italiano?, Espanyol?” till I told them I am an Indian. he promptly said Namaste and Dhanyawaad.

The former Einstein Cafe which served as a vantage point for espionage in cold war days

Some pictures from the Open air museum to the Berlin Wall, near Checkoint Charlie
Collage made by me. They show the historic moments in the history of the Wall

http://entertainment.time.com/2011/08/11/top-10-berlin-wall-movies/
TIME looks back at 10 movies that were set in the time of the Wall—and now have outlasted it.

Kennedy’s iconic visit to Checkpoint Charlie and the moment when Soviet tanks rolled up to Checkpoint Charlie
Soon after the construction of the Berlin Wall, a standoff occurred between U.S. and Soviet tanks on either side of Checkpoint Charlie. It began on 22 October as a dispute over whether East German guards were authorized to examine the travel documents of a U.S. diplomat named Allan Lightner passing through to East Berlin to see the opera.