After the declaration of independence in October 1830, Belgium was founded in 1831 as a constitutional parliamentary monarchy.
The first constitution provided for a unitary state: Political decisions were based on the principle of uniform legislation and central government. Certain powers were transferred very early to the subordinate bodies: the provinces and the local authorities, the municipalities, whose activities were subject to the supervision of the central state.
The Flemish Movement (1840), a cultural movement that sought the recognition of the Flemish language and culture, was born very quickly. The aim of this political movement was to introduce bilingualism in Belgium. In fact, the young country was officially monolingual: French was the only official language. Not only the Walloons, but also the Flemish upper middle classes were French-speaking, and Flemish was considered a dialect.
A few decades later, the Walloon Movement (1880) emerged. This movement had economic demands: Heavy industry, which made Belgium a leading economic power in Europe, stood in Wallonia. However, the Flemish electorate accounted for a larger share of the electorate: Most political decision-makers therefore came from the Flemish upper middle classes. The Walloon movement demanded greater autonomy for the region in order to manage heavy industry and thus economic development itself.
Because of the First World War, the two German districts of Eupen-Malmedy came to Belgium in 1920. The nine German-speaking communities of the area now form the German-speaking Community.
The cultural demands of the Flemish movement finally led in 1962 to the definition of the language borders or four language regions:

• the Flemish language area,
• the territory of the French language,
• the area of German language and
• the bilingual Brussels-Capital area (French / Dutch).

For the linguistic areas, the principle of territorial monolingualism has been established (except for Brussels and some special cases).
These linguistic areas formed the basis of the (cultural) communities created in the process of federalisation (1970).
The demands of the Walloon movement led to the creation of the regions in the process of federalisation.
In 1993, the Constitution was amended and since then it has started with the paragraph: "Belgium is a federal state composed of communities and regions". The former unitary state is thus history.

The three Communities:

• French Community,
• Flemish Community,
• German-speaking Community

are responsible for personal competences:

• Culture,
• Education,
• Health,
• Social.

The three regions:

• Flemish region,
• Walloon Region,
• Brussels Region Capital

are responsible for territorial competences:

• Economy,
• Spatial planning,
• Housing,
• Environment,
• Energy,
• Agriculture.

The territory of the comparatively small German-speaking Community (846.1 km² , 77,185 inhabitants, 91.2 inhabitants/km² on 1 January 2018) in the east of the country comprises the territory of the nine German-speaking municipalities, but is itself part of the territory of the Walloon Region.
Belgium is a founding member of the European Union.