Why has English become an important second language in Brussels?

English has become an important second language in Brussels primarily due to the city's role as a major international hub. Following World War II, Brussels became the headquarters for the European Union (EU) and NATO, leading to an influx of international personnel and a highly cosmopolitan population.123

While Brussels remains officially bilingual—with French serving as the primary lingua franca—English has overtaken Flemish as the most common second language among residents. This usage is largely concentrated in professional and educational settings rather than in the home. The city's status as the administrative and financial heart of Belgium, combined with its function as the capital of the "new Europe," has solidified the necessity of English as a tool for communication within its diverse, international workforce.123