This paper describes the history and contemporary constellation of language in Belgium as a protracted language-ideological debate. Belgium is often presented as a country whose political dynamics revolve around language: the fundamental ethnolinguistic difference between Dutch-speaking Flemish and French-speaking Walloons. Scholarly work as well as popular and media representations emphasize this language-focused political dynamics. This paper seeks to amend this view. Historically, the sociolinguistic-political history of Belgium is not linear, and contains several major turning points. This is explicable when we realize that language never occurred alone as a factor and argument in conflicts, but always operated as part, initially, of a larger democratization process and, later, as part of a power struggle due to momentous demographic and socio-economic transformations. Language was, in short, an emblematic argument that became shorthand for a larger set of issues. The most profound historical shift in Belgium's sociolinguistic history is language-ideological: the transformation of a bilingual and Jacobin hegemony to a monolingual Herderian one. This transformation now accounts for the recent emergence of two major problem zones: the denial of bilingualism as a social fact; and the selective rejection of forms of social, cultural and linguistic diversity as an effect of globalization. This rejection is selective, because English is now taking the precise place in the repertoires of Flemish youth as French did half a century ago.