The Prague Spring was a period of political liberalization in Czechoslovakia during the era of Soviet domination.

It began in early 1968 when a reformist leader, Alexander Dubček, came to power.

Dubček's goal was to create 'socialism with a human face,' a more democratic and liberal form of communism.

His reforms included the abolition of censorship, freedom of speech and press, and greater economic freedom.

The reforms were immensely popular with the Czechoslovak people and led to a flourishing of culture and political debate.

However, the Soviet Union and other hardline Warsaw Pact countries viewed the Prague Spring as a threat to their control over the Eastern Bloc.

In August 1968, the Soviet Union led a massive invasion of Czechoslovakia by Warsaw Pact forces to halt the reforms.

The Czechoslovak people responded with nonviolent civil resistance, but they were unable to stop the invasion.

The Prague Spring was crushed, Dubček was removed from power, and a hardline pro-Soviet government was installed.

The invasion was justified by the 'Brezhnev Doctrine,' which asserted the right of the USSR to intervene in any socialist country that was seen as deviating from communism.