(CNN)Here's some background information about the Berlin Wall, seen as a symbol of the Cold War and East/West relations. The wall stood from 1961 to 1989, separating democratic West Berlin, considered part of West Germany, from communist-controlled East Berlin and from the rest of East Germany.
The Berlin Wall evolved from a temporary border of barbed wire fencing to a heavily fortified, concrete barrier with numerous guards, tank traps and other obstacles.
February 1945 - In the waning days of World War II, the Allies' Yalta Conference divides Germany into four zones of occupation: Great Britain, France and the United States occupy the western and southern portions, and the Soviet Union occupies the eastern side. Berlin, located in Soviet territory, is also divided into zones.