Kelmis

After Napoleon's defeat in 1815, the Vienna Congress took place, in which many European borders were re-defined. Because of the important zinc mine and industry near Kelmis, the Unified Kingdom of the Netherlands (later Netherlands and Belgium), and the Kingdom of Prussia (which later became part of Germany) could not agree on whom the area belonged to. Hence they agreed to create a neutral area, with both countries appointing a commissioner to promote their country's interest in the area. The borders of the respective countries ended on the northeast and southwest, requiring exiting either country before entering the neutral area.

Although never a real state, the territory had a great similarity to one, completely with its own set of laws: due to the disputed ownership of the area, the countries agreed to keep Napoleonic law in force in the territory, with -missing an own court- Prussian and Belgian courts to interpret and judge according to that law. Also the separate and advantageous tax regime helped creating a great level of independence of the neighbouring states.

The zinc industry was the most important income of the country, however other income such as cheap goods, liquor and gambling has been important in bigger or smaller degrees over time.

With the Treaty of Versailles, the country became officially part of Belgium, thereby ending its century of independence. Nowadays it is part of the German speaking part of Belgium, placing it companionship with cities such as Eupen and St. Vith.