World War I

Flanders (and Belgium as a whole) saw some of the greatest loss of life on the Western Front of the First World War, in particular from the three battles of Ypres. Due to the hundreds of thousands of casualties at Ypres, the poppies that sprang up from the battlefield afterwards, later immortalized in the Canadian poem "In Flanders Fields", written by John McCrae, have become a symbol for lives lost in war.

Flemish feeling of identity and consciousness grew through the events and experiences of war. The occupying German authorities took several Flemish-friendly measures. More importantly, the experiences of many Dutch-speaking soldiers on the front led by French-speaking officers catalyzed Flemish emancipation. The French-speaking officers often gave orders in French only, followed by "et pour les Flamands, la même chose" which meant "and for the Flemish, the same thing" .  The resulting suffering is still remembered by Flemish organizations during the yearly Yser pilgrimage in Diksmuide at the monument of the Yser Tower.

During the interbellum and World War II, several right-wing fascist and/or national-socialistic parties emerged in Belgium, of which the Flemish ones drew unto the feeling of discrimination by the Wallonians against the Flemish. Since these parties were promised more rights for the Flemings by the German government during World War II, some of them collaborated with the Nazi regime. After the war, collaborators (or people who were "Zwart", "Black" during the war) were prosecuted and punished, among them many Flemish Nationalists whose main goal had been for more rights for Flanders. As a result, up until this day Flemish Nationalism is often associated with right-wing and fascist ideologies.