At the end of the sixth century, the Preacher Saint Gorik built a chapel on a small island formed by the two arms of the river Senne, creating the first building known to have been built in Brussels. Later, in A. D. 977, the first written record of Brussels declared Charles of France to be the legal owner of Low-Lorraine, including the island of Saint-Gorik, on which he built a fortress. But Brussels was not officially founded until 979, after Lambert of Leuven inherited the land from Charles. During the next three centuries, the city grew as a trading post and popular resting spot on the way to the channel ports, and the marshland surrounding the city slowly dried, opening up more land for habitation. The increased population put stress on the social system of guilds and noblemen, resulting in peasant uprisings that were quickly stifled during the thirteenth century. In 1402, construction on Grand Place began after 50 years of recession, and in 1430 Philip the Bold, Duke of Burgundy became the Duke of Brabant through marriage to Margaret, an heiress of the former ruler of Brussels, Duchess Joan. This period of relative calm was marked by a flowering of the arts and commerce in Brussels. The period of calm was shattered,

The Grand Place with the Hotel de Ville (City Hall) expresses traditional Flemish architectural design in the heart of Brussels. ()
however, when a plague killed about half of the city's 60,000 inhabitants in 1489. In 1507, Margaret of Austria was appointed General Governor of the Netherlands, and growth resumed in Brussels for a good 50 years.

The intrigues of Emporer Charles V and his successor Philip II brought revolution back to Brussels, as those sympathetic to William of Orange, supervisor of Holland (and champion of Charles V), fought against those who followed the Duke of Alva (favorite of William of Orange) in a battle for power over the city. Alva triumphed, only to be replaced by Isabella and Archduke Albert of Austria. Another plague outbreak, with losses comparable to the first, occurred in 1578, before Albert came into power in 1596. In 1695, Brussels was attacked by French King Louis XIV and his army, led by field marshal Villeroi, which destroyed more than 4,000 houses and Grand Place through fire and looting. The Royal Palace was burned down in 1731, and the French captured Brussels in 1746. This occupation lasted for about a century, until the Belgian revolution freed 138,000 Brussels citizens in 1830. On July 21, 1831, Leopold I became Belgium's first King, and the country rebuilt.

During World War I (1914–18), Brussels was an occupied city, but German troops did not incur much damage. The Germans returned during World War II (1939–45), resulting in Belgium's split into two semi-indepen-dent regions, the Flanders and Walloon Provinces, while the Brussels district had its own government. The Universal Exhibition took place in Brussels in 1958, and in 1970 construction of the Berlaymont building, house of the European government, began. The European Union and NATO moved their headquarters to Brussels, turning the city into quite an international meeting place for the twenty-first century.