Soviet leader Nikita Khrushchev had authorised the wall's construction, following a request by Walter Ulbricht, the leader of communist East Germany. Between 1949 and 1961, an estimated 2.5 million East Germans had crossed into the West, never to return. The effect on East Germany's economy was catastrophic - the exodus had to be stopped.
"Ich bin ein Berliner" The Americans, presented with a fait accompli, could do nothing to reverse the situation. U.S. President John F. Kennedy ordered more troops to guard West Berlin and the road corridor linking it to West Germany. In June, 1963, he made a symbolic visit to West Berlin, famously declaring: "Ich bin ein Berliner" (roughly: "I am a Berliner").
The wall became part of everyday life in Berlin and entered our national consciousness as a symbol of the Cold War. Berliners were not allowed to pass from one side to the other. Families were separated. People lost their livelihoods. Only routine military patrols and tourists were allowed to cross at the famous Checkpoint Charlie on the city's Friedrichstrasse.
Sixties spy novels and movies featured tense standoffs at Checkpoint Charlie. But, behind the stylised plots, lay real tragedy. Almost 200 people were killed trying to cross the wall and thousands more were arrested as they tried to flee to the West.
The Berlin Wall was strengthened over the years and a deadly no-man's land was created on the eastern side. But the wall crumbled in the face of pro-democracy agitation in the late 1980s. On November 9, 1989, travel restrictions between East and West Germany ended and the wall was confined to history. Almost immediately, Berliners began demolishing it themselves.
Today, just a few sections of the Berlin Wall remain as memorials. Elsewhere, a discreet double line of paving blocks on the ground marks the wall's former course.