German-Danish War: Destroyed Mill near Düppel/Jütland (1864) Prince Friedrich Karl of Prussia (fourth from right) and his staff in front of the destroyed Düppeler Mill. The storming of the fortifications at Düppel during the German-Danish War came to symbolize Prussian military efficiency and made the Danish defeat foreseeable. Unknown photographer, near Düppel/Jütland, April 18, 1864.