Prague Spring begins in Czechoslovakia
On August 20, 1968, the Soviet Union answered Dubcek’s reforms with invasion of Czechoslovakia by 600,000 Warsaw Pact troops. Prague was not eager to give way, but scattered student resistance was no match for Soviet tanks. Dubcek’s reforms were repealed, and the leader himself was replaced with the staunchly pro-Soviet Gustav Husak, who re-established an authoritarian Communist regime in the country.
In 1989, as Communist governments folded across Eastern Europe, Prague again became the scene of demonstrations for democratic reforms. In December 1989, Husak’s government conceded to demands for a multiparty Parliament. Husak resigned, and for the first time in two decades Dubcek returned to politics as chairman of the new Parliament, which subsequently elected playwright Vaclav Havel as president of Czechoslovakia. Havel had come to fame during the Prague Spring, and after the Soviet crackdown his plays were banned and his passport confiscated.
From: http://www.history.com/this-day-in-history/prague-spring-begins-in-czechoslovakia