November 9, 1989 marks the fall of the Berlin Wall in Germany but it was not until October 3, 1990, when East and West Berlin were united after 45 years of division.
It all started in 1945 after the Nazi surrendered to the Allied Four. Through the Potsdam agreement Germany was split into four zones which, at first would be governed by the USA, Great Britain, France and USSR. Their purpose was to run it as a single country, but due to ideological differences, the country was split into West Germany and East Germany. East Germany, being controlled by the Soviets and West Berlin or the free market west. East Germany closed its ties with the West in 1952 and in 1961 built the Wall in the city, preventing East Germans from escaping to West Germany.