Such imagery and symbols were adopted by many middle - class Germans who supported German nationalism .
The German historian Heinrich von Treitschke used imagery of the Teutonic Knights to promote pro-German and anti-Polish rhetoric .
Such imagery and symbols were adopted by many middle - class pro-German who supported pro-German nationalism .
The German historian Heinrich von Treitschke used imagery of the Teutonic Knights to promote pro-German and anti-Polish rhetoric .