Collection of facts about Czechoslovakia

This post is a collection of facts about Czechoslovakia (1918-1992). There are 10 facts listed below. Source: Wikipedia

• Gained independence from Austria-Hungary in 1918
• Lost the Sudetenland to Nazi Germany in 1938
• During World War II: Slovakia declared independence, Carpathian Ruthenia annexed by Hungary, Czech lands annexed by German Protectorate of Bohemia and Moravia 
• Third Czechoslovak Republic formed in 1945
• Part of the Eastern Bloc from 1948 to 1989
• Joined Comecon in 1949
• Signed Warsaw Pact in 1955
• Prague Spring liberalization in 1968 followed by Soviet Union invasion
• Velvet Revolution overthrew communist government in 1989
• Split into two countries (Czech Republic and Slovakia) in 1992