 During the period of Nazi occupation , some Belgians collaborated with their occupiers . There were pro @-@ Nazi political organizations in both Flemish and Walloon communities before and during the war . The most significant were DeVlag , Verdinaso and Vlaams Nationaal Verbond ( VNV ) in Flanders as well as the catholic Rex movement in Wallonia . Each of these movements had subtly different ideologies , their own paramilitary forces and printed their own newspapers . These organisations were also instrumental in encouraging Belgians to enlist into the German Army . Unlike the German @-@ style National Socialist agenda of DeVlag , VNV appealed directly to a Flemish separatist agenda , though this message was never the main source of their popularity . Infighting between the groups , particularly VNV and DeVlag , was considerable . 
