The catchment area included the newly annexed Province of Hesse-Nassau and the Thuringian principalities (Saxe-Weimar, Saxe-Meiningen, Saxe-Coburg and Gotha and Waldeck).

[2] It was still in existence at the end of the war[3] in the 6th Army, Heeresgruppe Kronprinz Rupprecht on the Western Front.

As the German Army expanded in the latter part of the 19th Century, a new XVIII Corps was formed on 1 April 1899 and took command of the 21st and 25th Divisions.

[5] The 25 peacetime Corps of the German Army (Guards, I - XXI, I - III Bavarian) had a reasonably standardised organisation.

The Corps was assigned to the VI Army Inspectorate in peacetime but joined the predominantly Saxon 3rd Army at the start of the First World War[15] forming part of the right wing of the forces for the Schlieffen Plan offensive in August 1914 on the Western Front.

It was still in existence at the end of the war[16] in the 6th Army, Heeresgruppe Kronprinz Rupprecht on the Western Front.