Brussels, officially the Brussels Capital-Region, is the de facto capital city of the European Union (EU) and the largest urban area in Belgium. It includes the Brussels municipality which is the capital of Belgium, Flanders and the French Community of Belgium by law.

Brussels has grown from a 10th-century fortress town founded by Charlemagne's grandson into a metropolis of more than one million inhabitants. The metropolitan area, including the outer commuter zone, covers a total area of 4,127 km2, covering the Capital-Region and 103 surrounding municipalities, and has a population of almost 2.7 million.

Since the end of the Second World War, Brussels has been an important centre for international politics. It hosts the main institutions of the European Union, and the headquarters of the North Atlantic Treaty Organization (NATO). Thus, Brussels is the polyglot home of many international organisations, politicians, diplomats and civil servants. Brussels is the EU's third-richest city in terms of per capita income.

Although historically Dutch-speaking, Brussels has become increasingly francophone. Today most inhabitants are native French-speakers, although both languages have official status. This process has led to a longstanding conflict between the French and Dutch speaking community, reflecting the situation in Belgium at large