Slovakia
The Slovak Republic and the Czech Republic went their separate ways after 1 January 1993, an event sometimes called the Velvet Divorce. Slovakia has remained a close partner with the Czech Republic. Both countries co-operate with Hungary and Poland in the Visegrád Group. Slovakia became a member of NATO on 29 March 2004 and of the European Union on 1 May 2004. On 1 January 2009, Slovakia adopted the Euro as its national currency.
Czech Republic
The remaining Czech territory was occupied by Germany, which transformed it into the so-called Protectorate of Bohemia and Moravia. The protectorate was proclaimed part of the Third Reich, and the president and prime minister were subordinated to the Nazi Germany's "Reichsprotektor". Subcarpathian Rus declared independence as the Republic of Carpatho-Ukraine on 15 March 1939 but was invaded by Hungary the same day and formally annexed the next day. Approximately 345,000 Czechoslovak citizens, including 277,000 Jews, were killed or executed while hundreds of thousands of others were sent to prisons and Nazi concentration camps or used as forced labor. Up to two-thirds of the citizens were in groups targeted by the Nazis for deportation or death. One concentration camp was located within the Czech territory at Terezín, north of Prague. The Nazi "Generalplan Ost" called for the extermination, expulsion, Germanization or enslavement of most or all Czechs for the purpose of providing more living space for the German people.