The Berlin Wall completely cut off the Western part of the German capital from the Eastern part and all of surrounding East Germany. It spanned 87 miles and was built in four stages.
The final version of the concrete wall, which was 3.6 metres high and had more than 116 guard towers, was completed in 1980.
It was reinforced with bunkers, fencing, barbed wire, trenches and guards with dogs.
The East German state claimed that they built the barrier to keep out fascist elements from West Germany, but few were convinced.
There were nine border crossings between East and West Berlin.
These allowed West Germans, Westerners and Allied personnel into the East, and East Germans and citizens of other Communist states into the West, if they had official permits.
The most famous of these was Checkpoint Charlie, which was restricted for use by Allied personnel and foreigners.
The wall was finally brought down in 1989.
As discontent grew in the Eastern Bloc, a mass movement took to the streets of East Germany demanding change. One million people protested in East Berlin at the beginning of November.
The protests forced the government to resign, and thousands went to border crossings demanding they be let through.
People then began to smash the wall, breaking through and pulling it down in celebration. Germany was reunified the following year.
For many workers in the East, the hoped for prosperity that free market capitalism was supposed to bring never appeared.
The market ripped through eastern European countries, destroying the lives of the poor while enriching a few.
This explains the nostalgia of some for the certainties of life in the East, though the economic crisis that had wracked the state in the run-up to 1989 meant poverty and shortages.
The brutality of the so-called Communist states discredited the idea of socialism for many people.
But their death helped a new generation explore the real vision of socialism—a theory of liberating humanity from all oppression and exploitation.