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.
German Zone of Protection in Slovakia
The German Zone of Protection in Slovakia, or the Protective Zone () was an area established in the western parts of the First Slovak Republic after the dissolution and division of Czechoslovakia by Nazi Germany during 1939. The special status of the zone was already created in the initial German-Slovak treaty of 23 March 1939, which defined the protective relationship between Germany and the Slovak State. The zone was codified by the German-Slovak treaty of August 28, 1939, which was signed in Bratislava ().