The units of the 25th Mixed Ersatz Brigade were from the VII Army Corps area, which included the Prussian Province of Westphalia, the Lower Rhine portion of the Prussian Rhine Province, the Principality of Lippe, and the Principality of Schaumburg-Lippe.

The units of the 43rd Mixed Ersatz Brigade were from the XI Army Corps area, which included the Hesse-Kassel (or Hesse-Cassel) portion of the Prussian Province of Hesse-Nassau, the Grand Duchy of Saxe-Weimar-Eisenach, the Duchies of Saxe-Coburg-Gotha and Saxe-Meiningen, the Principalities of Reuss Elder Line, Reuss Younger Line, Schwarzburg-Rudolstadt, Schwarzburg-Sondershausen, and Waldeck, and portions of the Prussian Province of Saxony, including the region around Erfurt.

It fought in the Battle of the Frontiers, seeing action in Lorraine and against the French defensive line from Nancy to Epinal.

The division remained in the Flanders/Artois region after the German offensives and faced the various Allied counteroffensives, seeing action in the late-1918 Battle of Cambrai.

It ended the war fighting in the Battle of Valenciennes and in the German retreat to its Antwerp-Meuse position.