On August 13, 1961 the East Germans, backed by Moscow, suddenly erected a temporary barbed wire barricade and then a concrete barrier, dividing Berlin.

The early period of Soviet troops marching into Berlin and plans of how to divide Berlin in sectors is documented.

War was averted, but the wall dividing Berlin became a corrosive global symbol of bitter oppression that would last for nearly three decades.

They also set up a four-power Allied Control Council for questions involving Germany as a whole, and they divided Berlin into four sectors.

Later, the land where the plaza stood became part of the "death strip" that divided Berlin.

I know that over the years many of you have seen the pictures and newsclips of the wall that divides Berlin.

This agreement was later formalised by the August 1945 Potsdam Agreement, which formally divided Berlin into four occupation sectors.

When the Allied Powers met at Potsdam they agreed to divide Germany into four occupation zones, and divided Berlin into four zones as well.

John Tagliabue's article "What Divides Berlin Now?"

Germany was de facto divided into two countries and two special territories, the Saarland and divided Berlin.