During the late seventies and through the eighties, Czechoslovakia suffered under Normalization, and while some of the other Warsaw Pact countries enjoyed a little more freedom, there was no let up for Czechoslovakia. In the Czech Lands, where Normalization was at its most severe, the dissident group Charter 77 was created, in protest to the strict regime.
Meanwhile, dissent in Slovakia mainly took place through the Catholic Church. A very religious people, the Slovaks gathered together for various pilgrimages during the calendar year, such as the Marianske Pilgrimage near Levoca, where thousands met to demonstrate there faith in God.
By the mid-eighties, and especially with the appointment of Michael Gorbacov as First Secretary of the Soviet Union, or 'Perestroika' was spreading from Moscow to the Warsaw Pact countries. However, while change was present in Russia, Hungary, Poland and eventually East Germany, change was slow coming in Czechoslovakia. It wasn't until November 1989, after the Berlin Wall had come down, that the Czechs and Slovaks rose up against the Communists in Mass protest. Without the support of Moscow, the puppet communist government knew it was pointless in continuing and resigned less than a month later.
The fact that the Czechs and Slovaks rose up against the Communists without any bloodshed, is why the uprising was dubbed the 'Velvet Revolution'.