In 1830, Brussels was confined to an area referred to as the pentagon, owing to its shape; it covered 415 hectares (ha). The population increase was a consequence of its role as the capital city and the development of trade and industry, and it quickly demonstrated the limits of this geographical area. The City of Brussels gradually had spread out during the nineteenth century and early twentieth century.
The city grew along three major axes, the eastern extension, the southern extension and the northern extension.
