Provinces of Belgium
During the second half of the 20th century, Belgium transitioned from a unitary state to a federal state with three Communities and three Regions. As part of the state reforms, the (bilingual) province of Brabant was split in 1995 three ways: into two (unilingual) provinces (Flemish Brabant and Walloon Brabant) and into the (bilingual) Brussels-Capital Region. (The Brussels-Capital Region does not belong to any province, is not a province, and does not contain any provinces.) The two new Brabant provinces became part of the Flemish Region and the Walloon Region respectively. The remaining eight provinces became part of these regions as well, so the Flemish Region and the Walloon Region each contain five provinces.
Belgian Federal Parliament
The number of seats in the Chamber is constitutionally set at 150 elected from 11 electoral districts. The districts are divided along linguistic lines: 5 Flemish (79 seats), 5 Walloon (49 seats), and the bilingual district of Brussels-Halle-Vilvoorde (22 seats).
The districts are the provinces, except for the districts of Leuven (part of Flemish Brabant) and Brussels-Halle-Vilvoorde. Each district is given a number of seats proportional to its population (not number of voters) ranging from 4 for Luxembourg to 24 for Antwerp.
All districts have an electoral threshold of 5%, except for Brussels-Halle-Vilvoorde and Leuven; all districts are monolingual, except for Brussels-Halle-Vilvoorde which encompasses both the 19 bilingual municipalities from the Brussels-Capital region and some 35 Dutch-speaking municipalities in Flemish Brabant, incl. 7 with language facilities for French-speakers.