[3][4][c] Besides the central historic town located within the Pentagon, the City of Brussels covers some of the city's immediate outskirts within the greater Brussels-Capital Region, namely the former municipalities of Haren, Laeken, and Neder-Over-Heembeek to the north, as well as the Avenue Louise/Louizalaan and the Bois de la Cambre/Ter Kamerenbos park to the south-east, where it borders municipalities in Flanders.

At the country's independence in 1830, the new members of the Belgian upper class hoped to create a new prestigious residential area in the capital.

An official plan for the Leopold Quarter was drawn up in 1838, marking the first major extension of the City of Brussels in its eastern part, following the transfer of a large area of the municipality of Saint-Josse-ten-Noode.

The area was designed to emanate from Brussels Park (located in front of the Royal Palace), and was laid out on a grid in a traditional classical pattern centred around the Square Frère Orban/Frère-Orbansquare.

[7][8][9] However, fierce resistance to the project was put up by the towns of Saint-Gilles and Ixelles—then, as now, separate municipalities (local authorities) from the City of Brussels—through whose territories the avenue was to run.

[10] After years of fruitless negotiations, the City of Brussels finally annexed the narrow band of land needed for the avenue, in addition to the Bois de la Cambre itself, in April 1864.

Further east, in 1880, a former military exercise ground and the surrounding land, also located in Etterbeek, were attached to the City to create the Parc du Cinquantenaire/Jubelpark, an exhibition space commemorating the 50th anniversary of independence.

Akin to neighbouring Ixelles, Etterbeek and Schaerbeek, the City of Brussels also has a large Muslim population, mainly of North African origin.

As of 2023[update], taking into account the nationality of birth of the parents, 55.84% of the City of Brussels's population is of non-European origin (predominantly Moroccan, Indian and Congolese), 27.21% is of European origin other than Belgian (mainly French, Romanian, Italian, Spanish, and Polish), while 16.94% is solely of native Belgian ancestry.

[20] The current mayor of the City of Brussels is Philippe Close, a member of PS, who is in coalition on the municipal council with Ecolo - Groen, DéFI and Forward.