United Kingdom of the Netherlands

Historians use the name United Kingdom of the Netherlands for the kingdom that joined the northern and southern Low Countries under King William I of the House of Orange-Nassau between 1815 and 1839. Built after the Napoleonic Wars from the former Dutch Republic, the Austrian Netherlands and the lands of the prince-bishops of Liège, it was meant as a strong buffer state on France's northern border. The Belgian Revolution of 1830 split it in practice, and the split became final in 1839.

Before the French Revolutionary Wars the Low Countries were a patchwork left by the Eighty Years' War. In the north stood the independent Dutch Republic; the south was split between the Austrian Netherlands, ruled by the Habsburgs, and the Prince-Bishopric of Liège. French armies overran the south in 1794 and annexed it, and the Dutch Republic fell in 1795, becoming a French client state.

In 1813 Prussian and Russian troops drove the French out of the north. Leaders of the provisional government, many of whom had helped expel the House of Orange eighteen years earlier, preferred to recall William Frederick, son of the last stadtholder, themselves before the Allies could install him. He became sovereign prince of the United Netherlands. By the secret Eight Articles of London in June 1814, the Great Powers assigned him the south as well, and that August he became governor-general of the former Austrian Netherlands and Liège. During Napoleon's Hundred Days he proclaimed himself King William I on 16 March 1815. At the Congress of Vienna he ceded the Principality of Orange-Nassau and parts of Liège to Prussia on 31 May 1815 and received Luxembourg, raised to a grand duchy and held in personal union with the crown while remaining part of the German Confederation. The constitution was adopted on 24 August 1815.

The kingdom was a constitutional monarchy, but the king held much more power than later Dutch or Belgian monarchs; ministers answered to him. A two-chamber States General sat beneath him. There were seventeen provinces plus Luxembourg, and overseas possessions included the East Indies, Surinam, Curaçao and posts on the Gold Coast.

The economy did well. With state backing, the Industrial Revolution took hold in the south, where John Cockerill founded a steel industry in Wallonia, and Antwerp became a major port. In 1817 new universities opened at Leuven, Liège and Ghent. A society to promote national industry followed in 1822, and the Netherlands Trading Society in 1825 to develop colonial commerce, while canals such as the North Holland and the Brussels–Charleroi were dug.

The two halves never fully merged. The south was strongly Catholic and the north mainly Dutch Reformed, and the Catholic Church resented state interference, especially in schools. William made Dutch the sole official language in the Dutch-speaking southern provinces and pushed it into schools in Wallonia, a policy disliked by the French-speaking elite. Southerners made up about 62 percent of the population but had only half the seats in the lower house, and many believed southern wealth was subsidising the north. By the mid-1820s liberals and Catholic conservatives in the south had joined in opposition.

Inspired by the July Revolution in France, revolt broke out in Brussels on 25 August 1830. Troops sent in September failed to retake the city, and on 4 October Belgium declared independence, later choosing Leopold I as king. William refused to accept the loss and in August 1831 invaded in the Ten Days' Campaign, but French intervention forced him back. Only in 1839, by the Treaty of London, did the Netherlands recognise Belgian independence, with territorial concessions; the frontier was fixed in 1843.

Our 1815 map shows the United Kingdom of the Netherlands in its first year, joining the lands of today's Netherlands and Belgium under one crown.