List of presidents of Czechoslovakia
The president of Czechoslovakia (Czech: prezident Československa, Slovak: prezident Česko-Slovenska) was the head of state of Czechoslovakia, from the creation of the First Czechoslovak Republic in 1918 until the dissolution of the Czech and Slovak Federative Republic on 1 January 1993. In periods when the presidency was vacant, most presidential duties were assumed by the prime minister.
Source: Wikipedia — List of presidents of Czechoslovakia (CC BY-SA 4.0)