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.
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 ().