Czech Republic–Slovakia relations
Before 1918, both countries were part of Austria–Hungary. However, after the Ausgleich of 1867 Czechia belonged to the Austrian Empire while Slovakia belonged to the administratively separate Kingdom of Hungary, and between 1918 and December 31, 1992, both countries were part of Czechoslovakia. 
Both countries established diplomatic relations on January 1, 1993. These international relations are usually referred to or described as "very good", "cordial", and "above standard" in the media. When a Czech or Slovak president is inaugurated, very often his first international visit is to the former part of the common country. The same custom applies to newly elected prime ministers of the Czech Republic and Slovakia.
Czech Socialist Republic
After the occupation of Czechoslovakia in 1968, liberalisation reforms were stopped and reverted. The only exception was the federalization of the country. The former centralist state Czechoslovakia was divided in two parts: the "Czech Socialist Republic" and the "Slovak Socialist Republic" by the Constitutional Law of Federation of 28 October 1968, which went into effect on 1 January 1969. New national parliaments (the Czech National Council and the Slovak National Council) were created and the traditional parliament of Czechoslovakia was renamed the "Federal Assembly" and was divided in two chambers: the "House of the People" (, ) and the "House of Nations" (, ). Very complicated rules of voting were put in effect.