XXI Corps (German Empire)

The XXI Army Corps / XXI AK (German: XXI. Armee-Korps) was a corps level command of the German Army, before and during World War I.

XXI Army Corps XXI. Armee-Korps
Flag of the Staff of a Generalkommando (1871–1918)
Active	1 October 1912 (1912-10-01)–1919 (1919)
Country	German Empire
Branch	Army
Type	Corps
Size	Approximately 44,000 (on mobilisation in 1914)
Garrison/HQ	Saarbrücken/Landgericht, Hindenburgstraße
Shoulder strap piping	Light Green
Engagements	World War I Battle of the Frontiers
Insignia
Abbreviation	XXI AK

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 (headquarters) for the districts of Koblenz, Trier and part of Alsace-Lorraine.^[1] It took over command of 31st Division from XV Corps and the newly formed 42nd Division (the last division to be formed by the peacetime army). General der Infanterie Fritz von Below, former commander of 1st Guards Division, took command.^[2]

It was assigned to the VII Army Inspectorate.^[3] 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^[4] in the 5th Army, Heeresgruppe Gallwitz on the Western Front.^[5]

Peacetime organisation

The 25 peacetime Corps of the German Army (Guards, I - XXI, I - III Bavarian) had a reasonably standardised organisation. Each consisted of two divisions with usually two infantry brigades, one field artillery brigade and a cavalry brigade each.^[6] 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:

V, VI, VII, IX and XIV Corps each had a 5th infantry brigade (so 10 infantry regiments)

II, XIII, XVIII and XXI had a 9th infantry regiment

I, VI and XVI Corps had a 3rd cavalry brigade (so 6 cavalry regiments)

the Guards Corps had 11 infantry regiments (in 5 brigades) and 8 cavalry regiments (in 4 brigades).^[7]

Each Corps also directly controlled a number of other units. This could include one or more

Foot Artillery Regiment

Jäger Battalion

Pioneer Battalion

Train Battalion

Peacetime organization of the Corps^[8]

Corps	Division	Brigade	Units	Garrison
XXI Corps	31st Division	32nd Infantry Brigade	70th (8th Rhenish) Infantry	Saarbrücken
			174th (10th Lotharingian) Infantry	Forbach
		62nd Infantry Brigade	60th (7th Brandenburg) Infantry "Margrave Charles"	Weißenburg
			137th (2nd Lower Alsatian) Infantry	Hagenau
			166th (Hessen-Homburg) Infantry	Bitsch
		31st Field Artillery Brigade	31st (1st Lower Alsatian) Field Artillery	Hagenau
			67th (2nd Lower Alsatian) Field Artillery	Hagenau, Bischweiler
		31st Cavalry Brigade	7th (Westphalian) Dragoons	Saarbrücken
			7th (Rhenish) Uhlans "Archduke Frederick of Baden"	Saarbrücken
	42nd Division	59th Infantry Brigade	97th (1st Upper Rhenish) Infantry	Saarburg
			138th (3rd Lower Alsatian) Infantry	Dieuze
		65th Infantry Brigade	17th (4th Westphalian) Infantry "Count Barfuss"	Mörchingen
			131st (2nd Lotharingian) Infantry	Mörchingen
		42nd Field Artillery Brigade	8th (1st Rhenish) Field Artillery "von Holtzendorff"[9]	Saarbrücken
			15th (1st Upper Alsatian) Field Artillery[10]	Saarburg, Mörchingen
		42nd Cavalry Brigade	11th (2nd Brandenburg) Uhlans "Count Haeseler"	Saarburg
			15th (Schleswig-Holstein) Uhlans	Saarburg
	Corps Troops		3rd Machine Gun Abteilung	Saarburg
			27th (2nd Rhenish) Pioneer Battalion	Trier
			21st (2nd Rhenish) Train Battalion	Forbach
	Saarbrücken Defence Command (Landwehr-Inspektion)			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^[11] 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 (54 machine guns), 8 cavalry squadrons, 24 field artillery batteries (144 guns), 4 heavy artillery batteries (16 guns), 3 pioneer companies, and an aviation detachment.

Initial wartime organization of the Corps^[12]

Corps	Division	Brigade	Units
XXI Corps	31st Division	32nd Infantry Brigade	70th Infantry Regiment
			174th Infantry Regiment
		62nd Infantry Brigade	60th Infantry Regiment
			137th Infantry Regiment
			166th Infantry Regiment
		31st Field Artillery Brigade	31st Field Artillery Regiment
			67th Field Artillery Regiment
			7th Uhlan Regiment
			1st Company, 27th Pioneer Battalion
			31st Divisional Pontoon Train
			1st Medical Company
	42nd Division	59th Infantry Brigade	97th Infantry Regiment
			138th Infantry Regiment
		65th Infantry Brigade	17th Infantry Regiment
			131st Infantry Regiment
		42nd Field Artillery Brigade	8th 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 Troops		II Battalion, 3rd Foot Artillery Regiment[13]
			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^[14] in the 5th Army, Heeresgruppe Gallwitz on the Western Front.^[15]

Commanders

The XXI Corps had the following commanders during its existence:^[16][17]

Dates	Rank	Name
1 October 1912 to 4 April 1915	General der Infanterie	Fritz von Below
4 April 1915 to 2 January 1917	Generalleutnant	Oskar von Hutier
2 January 1917 to end of war	Generalleutnant	Ernst von Oven

See also

• Germany portal

• German Army order of battle (1914)
• German Army order of battle, Western Front (1918)
• List of Imperial German infantry regiments
• List of Imperial German artillery regiments
• List of Imperial German cavalry regiments

References

1. German Administrative History Accessed: 9 April 2012
2. "The Prussian Machine". Archived from the original on 4 December 2013. Retrieved 9 April 2012.
3. Cron 2002, p. 395
4. Cron 2002, pp. 88–89
5. Ellis & Cox 1993, pp. 186–187
6. Haythornthwaite 1996, pp. 193–194
7. They formed the Guards Cavalry Division, the only peacetime cavalry division in the German Army.
8. War Office 1918, p. 260
9. Had a third (Horse Artillery) Abteilung of three batteries of 4 guns.
10. Had a third (Horse Artillery) Abteilung of three batteries of 4 guns.
11. Cron 2002, p. 300
12. Cron 2002, pp. 317–318
13. 4 heavy artillery batteries (16 heavy field howitzers)
14. Cron 2002, pp. 88–89
15. Ellis & Cox 1993, pp. 186–187
16. German Administrative History Accessed: 9 April 2012
17. German War History Accessed: 9 April 2012

Bibliography

• Cron, Hermann (2002). Imperial German Army 1914-18: Organisation, Structure, Orders-of-Battle [first published: 1937]. Helion & Co. ISBN 1-874622-70-1.
• Ellis, John; Cox, Michael (1993). The World War I Databook. Aurum Press Ltd. ISBN 1-85410-766-6.
• Haythornthwaite, Philip J. (1996). The World War One Source Book. Arms and Armour. ISBN 1-85409-351-7.
• Histories of Two Hundred and Fifty-One Divisions of the German Army which Participated in the War (1914-1918), compiled from records of Intelligence section of the General Staff, American Expeditionary Forces, at General Headquarters, Chaumont, France 1919. The London Stamp Exchange Ltd (1989). 1920. ISBN 0-948130-87-3.
• The German Forces in the Field; 7th Revision, 11th November 1918; Compiled by the General Staff, War Office. Imperial War Museum, London and The Battery Press, Inc (1995). 1918. ISBN 1-870423-95-X.