XXI Corps (German Empire)


The XXI Army Corps / XXI AK was a corps level command of the German Army, before and during World War I.
As the German Army expanded in the latter part of the 19th century and early part of the 20th century, the XXI Army Corps was set up on 1 October 1912 in Saarbrücken as the Generalkommando for the districts of Koblenz, Trier and part of Alsace-Lorraine. It took over command of 31st Division from XV Corps and the newly formed 42nd Division. General der Infanterie Fritz von Below, former commander of 1st Guards Division, took command.
It was assigned to the VII Army Inspectorate. but joined the predominantly Bavarian 6th Army at the start of the First World War. It was still in existence at the end of the war in the 5th Army, Heeresgruppe Gallwitz on the Western Front.

Peacetime organisation

The 25 peacetime Corps of the German Army had a reasonably standardised organisation. Each consisted of two divisions with usually two infantry brigades, one field artillery brigade and a cavalry brigade each. Each brigade normally consisted of two regiments of the appropriate type, so each Corps normally commanded 8 infantry, 4 field artillery and 4 cavalry regiments. There were exceptions to this rule:
Each Corps also directly controlled a number of other units. This could include one or more
CorpsDivisionBrigadeUnitsGarrison
XXI Corps31st Division32nd Infantry Brigade70th InfantrySaarbrücken
174th InfantryForbach---
62nd Infantry Brigade60th Infantry "Margrave Charles"Weißenburg--
137th InfantryHagenau---
166th InfantryBitsch---
31st Field Artillery Brigade31st Field ArtilleryHagenau--
67th Field ArtilleryHagenau, Bischweiler---
31st Cavalry Brigade7th DragoonsSaarbrücken--
7th Uhlans "Archduke Frederick of Baden"Saarbrücken---
42nd Division59th Infantry Brigade97th InfantrySaarburg-
138th InfantryDieuze---
65th Infantry Brigade17th Infantry "Count Barfuss"Mörchingen--
131st InfantryMörchingen---
42nd Field Artillery Brigade8th Field Artillery "von Holtzendorff"Saarbrücken--
15th Field ArtillerySaarburg, Mörchingen---
42nd Cavalry Brigade11th Uhlans "Count Haeseler"Saarburg--
15th UhlansSaarburg---
Corps Troops3rd Machine Gun AbteilungSaarburg-
27th Pioneer BattalionTrier---
21st Train BattalionForbach---
Saarbrücken Defence Command
Saarbrücken-

World War I

Organisation on mobilisation

On mobilization on 2 August 1914 the Corps was restructured. 42nd Cavalry Brigade was withdrawn to form part of the 7th Cavalry Division and the 31st Cavalry Brigade was broken up and its regiments assigned to the divisions as reconnaissance units. Divisions received engineer companies and other support units from the Corps headquarters. Unusually, the Corps retained its 9th infantry regiment on mobilisation. In summary, XXI Corps mobilised with 27 infantry battalions, 9 machine gun companies, 8 cavalry squadrons, 24 field artillery batteries, 4 heavy artillery batteries, 3 pioneer companies, and an aviation detachment.
CorpsDivisionBrigadeUnits
XXI Corps31st Division32nd Infantry Brigade70th Infantry Regiment
174th Infantry Regiment---
62nd Infantry Brigade60th Infantry Regiment--
137th Infantry Regiment---
166th Infantry Regiment---
31st Field Artillery Brigade31st Field Artillery Regiment--
67th Field Artillery Regiment---
7th Uhlan Regiment--
1st Company, 27th Pioneer Battalion---
31st Divisional Pontoon Train---
1st Medical Company---
42nd Division59th Infantry Brigade97th Infantry Regiment-
138th Infantry Regiment---
65th Infantry Brigade17th Infantry Regiment--
131st Infantry Regiment---
42nd Field Artillery Brigade8th Field Artillery Regiment--
15th Field Artillery Regiment---
7th Dragoon Regiment--
2nd Company, 27th Pioneer Battalion---
3rd Company, 27th Pioneer Battalion---
42nd Divisional Pontoon Train---
2nd Medical Company---
3rd Medical Company---
Corps TroopsII Battalion, 3rd Foot Artillery Regiment-
8th Aviation Detachment---
21st Corps Pontoon Train---
21st Telephone Detachment---
27th Pioneer Searchlight Section---
Munition Trains and Columns corresponding to II Corps---

Combat chronicle

On mobilisation, XXI Corps was assigned to the predominantly Bavarian 6th Army forming part of the left wing of the forces for the Schlieffen Plan offensive in August 1914 on the Western Front. By 1915 it was on the Eastern Front where it took part in the siege of Kovno and the battles on the Neman River and at Vilnius. It was still in existence at the end of the war in the 5th Army, Heeresgruppe Gallwitz on the Western Front.

Commanders

The XXI Corps had the following commanders during its existence:
DatesRankName
1 October 1912 to 4 April 1915General der InfanterieFritz von Below
4 April 1915 to 2 January 1917GeneralleutnantOskar von Hutier
2 January 1917 to end of warGeneralleutnantErnst von Oven