Czechoslovak Socialist Republic

The Czechoslovak Socialist Republic, (Czech and Slovak: Československá socialistická republika, ČSSR) known from 1948 to 1960 as the Czechoslovak Republic (Československá republika), Fourth Czechoslovak Republic, or simply Czechoslovakia, was the Czechoslovak state from 1948 until 1989, when the country was under communist rule, and was regarded as a satellite state in the Soviet sphere of interest. Following the coup d'état of February 1948, when the Communist Party of Czechoslovakia seized power with the support of the Soviet Union, the country was declared a "people's democratic state" when the Ninth-of-May Constitution became effective.

Source: Wikipedia — Czechoslovak Socialist Republic (CC BY-SA 4.0)