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.
Jozef Tiso
Slovakia became the Slovak Republic, an independent state (under German protection) which was formally recognised by the Soviet Union and Germany, with "de facto" recognition by Great Britain and France (but not by the United States who were largely responsible, in 1919, for the new artificial state of Czechoslovakia). Czech émigrés and the United States considered Slovakia a puppet state of Germany. After the later recognition of the Czechoslovak government-in-exile by Great Britain, the British Foreign Office notified the Czech Foreign Ministry that Britain did not recognise any territorial claims of Czechoslovakia, nor could they commit to any fixed boundaries for the state, nor recognise the legal continuation of Czechoslovakia.