The Prague Spring was a period of political liberalization and mass protest in the Czechoslovak Socialist Republic. It began on 5 January 1968, when reformist Alexander Dubček was elected First Secretary of the Communist Party of Czechoslovakia (KSČ), and continued until 21 August 1968, when the Soviet Union and most of Warsaw Pact members invaded the country to suppress the reforms.

The Prague Spring reforms were a strong attempt by Dubček to grant additional rights to the citizens of Czechoslovakia in an act of partial decentralization of the economy and democratization. The freedoms granted included a loosening of restrictions on the media, speech and travel. After national discussion of dividing the country into a federation of three republics, Bohemia, Moravia-Silesia and Slovakia, Dubček oversaw the decision to split into two, the Czech Socialist Republic and Slovak Socialist Republic. This dual federation was the only formal change that survived the invasion.