With the rise of Napoleon, French rule over Belgium became more constructive, including the revitalization of industry and (with the opening of the Scheldt) the partial recovery of Antwerp. With Napoleon's fall, the great Allied powers decreed that Belgium would become a part of the Kingdom of the Netherlands, ruled by the pro-Dutch William of Orange. By 1830 the Belgians' patience had run out. Revolution erupted in Brussels and quickly spread across the country. William made a brief effort to regain control, but within a few months he withdrew. On 20 January, 1831, after centuries of external rule, Belgium was recognized as an independent nation.

The Belgians chose Leopold of Saxe-Coburg to be their first King, under a constitution that significantly limited the power of the monarchy . Under Leopold I and then his son Leopold II, Belgium flourished both economically and culturally. It was Leopold II who acquired the Congo, which remained a part of Belgium until its independence in 1960.Leopold II was succeeded in 1909 by Albert I, his nephew.. Albert's reign was dominated by World War I, during which most of the country fell under extremely harsh German occupation despite determined resistance. The Belgian army survived the invasion, and it played a central role in retaking the country at the end of the war. Albert lived until 1934, when he died in a tragic climbing accident. His wife Elisabeth is remembered as a great patron of the arts. Together with Eugene Ysaye, she founded the world-renowned Queen Elisabeth Contest, Belgium's foremost musical competition.

Albert was succeeded by his son Leopold III, who like his father was soon confronted by war. In 1940, Germany invaded Belgium and Holland. As the blitzkrieg swept across the country, the Belgian government evacuated to London. Leopold, however, surrendered to the German forces when the Belgian lines at Kortrijk were broken. The territories of Eupen, Malmedy and St. Vith were annexed to the German Reich and the rest of Belgium occupied. Leopold was held prisoner in the palace of Laeken before being taken to Germany. When the Allied Forces liberated Belgium at the beginning of 1944, popular feeling against Leopold was substantial, and his brother Prince Charles assumed regency. Leopold III returned to Belgium in 1950, but popular opposition to his rule remained substantial. In 1951, he abdicated in favour of his son Baudoin. In the post-war period, Brussels has gradually taken on its role as the 'capital' of Europe. It is the headquarters of the European Community and the North Atlantic Treaty Organization, as well as gaining a reputation as the foremost European center of international business. In 1957, Belgium formed, with the Netherlands and Luxembourg, the Benelux Union.

Perhaps the most significant of the postwar developments has been the increasing local autonomy of various regions of the country. In 1977 the country was divided into three administrative regions: Flanders, Wallonia, and Brussels. In 1980, the Belgian constitution was changed to recognize this separation, shifting the structure of the nation to a federation. In 1995, the provinces of Flemish Brabant and Walloon Brabant were created from the old province of Brabant, leaving Belgium with a total of 10 provinces. When King Baudoin died in 1993, his brother Albert II succeeded to the throne. Albert II is married to Paola Ruffo di Calabria. The Royal couple has three children, Prince Philip (the official heir to the throne), Princess Astrid (who is married to Archduke Lorenz of Austria), and Prince Laurent.