The Berlin Wall - the single most potent symbol of the Cold War - is torn down in an incredible display of "people power". Gorbachev could still use force to prop up his collapsing empire: the world watches as the wall is hacked away, waiting to see if he will act. He chooses not to. Scenes of joy are broadcast around the world as families and neighbours are united. Only months earlier those who tried it risked being shot.
Czechoslovakia is the next country to break free. The "Velvet Revolution" bloodlessly ousts the communists and installs playwright Vaclav Havel as president.
As the year draws to a close, Romanians also go for revolution. This time there is bloodshed, as riots erupt in the city of Timisoara, but the ruthless reign of President Ceausescu ends. He and his wife are executed on Christmas Day.
But as freedom is extended across the Soviet bloc, Gorbachev is becoming more unpopular at home. Shortages have worsened since his economic reforms began, and living standards are falling. Dissatisfaction with perestroika starts to take hold.