Dissolution of Czechoslovakia
Since the federalization in 1968, Czechoslovakia had divided citizenship, either of the Czech Socialist Republic or of the Slovak Socialist Republic (the word 'Socialist' was dropped from both names shortly after the Velvet Revolution). This distinction, however, had little effect on the citizen's life. On January 1, 1993, all Czechoslovak citizens automatically became citizens either of the Czech Republic or the Slovak Republic, based on their previous citizenship, permanent residence address, birthplace, family ties, job, and other criteria. Additionally, people had one year's time to claim the other citizenship under certain conditions.
Origins of Czechoslovakia
Both Czechs and Slovaks struggled against a powerful neighbouring people; Germans in the case of the Czechs, Hungarians in the case of the Slovaks (see History of the Czech Republic and History of Slovakia). Contacts between the Czechs and Slovaks arose in the late fourteenth century, when Slovaks started to study at the University of Prague; in the fifteenth century, with the campaigns of the Czech Hussite armies to Slovakia; and in the seventeenth century, when Czech Protestants fled to Slovakia. Between the fifteenth and eighteenth centuries, some educated Slovaks used written Czech as well as Slovak and Latin (see History of the Slovak language). The Czechs and Slovaks were also formally united in 1436–1439, 1453–1457, and 1490–1918, when Hungary (which included Slovakia), Bohemia and other Central European states were ruled by the same kings.