Czechoslovakia or Czecho-Slovakia in both of those languages) was a sovereign state in Central Europe that existed from October 1918, when it declared its independence from the Austro-Hungarian Empire, until its peaceful dissolution into the Czech Republic and Slovakia on 1 January 1993.
From 1939 to 1945, following its forced division and partial incorporation into Nazi Germany, the state did not de facto exist but its government-in-exile continued to operate. On 29 June 1945, a treaty was signed between Czechoslovakia and the Soviet Union, ceding Carpatho-Ukraine to the USSR.
From 1948 to 1990 Czechoslovakia was part of the communist Warsaw Pact and had a command or planned economy. A period of political liberalization in 1968, known as the Prague Spring, was forcibly ended when several other Warsaw Pact countries invaded. In 1989, as communism was ending all over Europe, Czechoslovaks peacefully deposed their government in the Velvet Revolution; socialist price controls were removed after a period of preparation. A few years afterwards, in 1993 the country was separated into two sovereign states, again peacefully.