The 18th Reserve Division fought on the
Western Front alongside its sister division, the 17th Reserve Division. It fought across Belgium in August 1914 and then occupied the line on the Aisne until September 1915. It then went to Flanders and the Artois, where it remained engaged in positional warfare until June 1916. From mid-July to late October 1916, it fought in the
Battle of the Somme with only one interlude away from the front. The division then remained in the trenchlines along the Yser until May 1917. In May it fought in the
Battle of Arras. It remained in the Flanders region for the rest of the year and into 1918 and fought in the
Battle of Passchendaele. In 1918, it occupied various parts of the line and fought against several Allied offensives, including in the second
Battle of Cambrai. In 1918, Allied intelligence rated the division as second class. ==Order of battle on mobilization==