The Francization of Brussels refers to the evolution, over the past two centuries,[1][2] of this historically Dutch-speaking city[1][3][4] into one where French has become the majority language and lingua franca.[5] The main cause of this transition was the rapid, yet compulsory assimilation of the Flemish population,[6][1][7][8][4] amplified by immigration from France and Wallonia.[1][9]