Kingdom of the United Netherlands

United Kingdom of the Netherlands
Verenigd Koninkrijk der Nederlanden  (Dutch) Royaume-Uni des Pays-Bas  (French)
1815–1839
Flag Coat of arms
Motto "Je maintiendrai" (French) "I will uphold"
Anthem Wien Neêrlands Bloed "Those in whom Dutch blood"
Location of the United Kingdom of the Netherlands (dark green) in 1815 in Europe (dark grey). The Grand Duchy of Luxembourg (light green) is also shown.
Capital		Amsterdam and Brussels
Languages		Dutch (official) and French (official in Wallonia)
Religion		Dutch Reformed Roman Catholic
Government		Constitutional monarchy
King
•	1815–1839	William I
Legislature		States General
•	Upper house	Senate
•	Lower house	House of Representatives
Historical era		Late modern period
•	Congress of Vienna	16 March 1815
•	Constitution adopted	24 August 1815
•	Belgian Revolution	25 August 1830
•	Treaty of London	19 April 1839
Currency		Dutch guilder
Preceded by Succeeded by First French Empire Netherlands Duchy of Limburg (1839–1867) Luxembourg Belgium

The United Kingdom of the Netherlands (Dutch: Verenigd Koninkrijk der Nederlanden; French: Royaume-Uni des Pays-Bas) is the unofficial name given to the Kingdom of the Netherlands as it existed between 1815 and 1839. The United Netherlands was created in the aftermath of the Napoleonic Wars through the fusion of territories that had belonged to the former Dutch Republic, Austrian Netherlands, and Prince-Bishopric of Liège. The polity was a constitutional monarchy, ruled by William I of the House of Orange-Nassau.

The polity collapsed in 1830 with the outbreak of the Belgian Revolution. With the de facto secession of Belgium, the Netherlands was left as a rump state and refused to recognise Belgian independence until 1839 when the Treaty of London was signed, fixing the border between the two states and guaranteeing Belgian independence and neutrality as the Kingdom of Belgium.

Before the French Revolutionary Wars (1792-1802), the Low Countries was a patchwork of different polities created by the Eighty Years' War (1568-1648). The Dutch Republic in the north was independent, while the Southern Netherlands was split between the Austrian Netherlands and Prince-Bishopric of Liège. The former was part of Habsburg Austria and both were part of the Holy Roman Empire. In the aftermath of the French Revolution, the War of the First Coalition broke out in 1792 and France was invaded by Prussia and the Holy Roman Empire. After two years of fighting, the Austrian Netherlands and Liège were captured by the French in 1794 and annexed into France. The Dutch Republic collapsed in 1795 and became a French client state.