Antwerp is a city and a municipality in the Flemish Region of Belgium. It is the capital and largest city of Antwerp Province, and the third largest city in Belgium by area at 204.51 km2 (78.96 sq mi) after Tournai and Couvin. With a population of 536,079, it is the most populous municipality in Belgium, and with a metropolitan population of over 1,200,000 people, the country's second-largest metropolitan region after Brussels.

Brussels, officially the Brussels-Capital Region, is a region of Belgium comprising 19 municipalities, including the City of Brussels, which is the capital of Belgium. The Brussels-Capital Region is located in the central portion of the country and is a part of both the French Community of Belgium and the Flemish Community, but is separate from the Flemish Region and the Walloon Region, located less than 4 kilometres (2.5 mi) to the south. Historically Dutch-speaking, Brussels saw a language shift to French from the late 19th century. Nowadays, the Brussels-Capital Region is officially bilingual in French and Dutch, although French is the majority language and lingua franca. Brussels is also increasingly becoming multilingual. English is spoken widely and many migrants and expatriates speak other languages as well.