The 21st Division (''21. Division'') was a unit of the

Prussia Prussia, , Old Prussian: ''Prūsa'' or ''Prūsija'' was a German state on the southeast coast of the Baltic Sea. It formed the German Empire under Prussian rule when it united the German states in 1871. It was ''de facto'' dissolved by an em ...

German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ger ...

Army An army (from Old French ''armee'', itself derived from the Latin verb ''armāre'', meaning "to arm", and related to the Latin noun ''arma'', meaning "arms" or "weapons"), ground force or land force is a fighting force that fights primarily on ...

. It was formed on October 11, 1866, and was headquartered in

Frankfurt am Main Frankfurt, officially Frankfurt am Main (; Hessian: , "Frank ford on the Main"), is the most populous city in the German state of Hesse. Its 791,000 inhabitants as of 2022 make it the fifth-most populous city in Germany. Located on its na ...

. The division was subordinated in peacetime initially to the XI Army Corps (''XI. Armeekorps'') and from 1899 to the XVIII Army Corps (''XVIII. Armeekorps''). The division was recruited in the formerly independent

Duchy of Nassau The Duchy of Nassau (German: ''Herzogtum Nassau'') was an independent state between 1806 and 1866, located in what is now the German states of Rhineland-Palatinate and Hesse. It was a member of the Confederation of the Rhine and later of the G ...

and the

Electorate of Hesse The Electorate of Hesse (german: Kurfürstentum Hessen), also known as Hesse-Kassel or Kurhessen, was a landgraviate whose prince was given the right to elect the Emperor by Napoleon. When the Holy Roman Empire was abolished in 1806, its prin ...

, which had been incorporated into Prussia after the

Austro-Prussian War The Austro-Prussian War, also by many variant names such as Seven Weeks' War, German Civil War, Brothers War or Fraternal War, known in Germany as ("German War"), (; "German war of brothers") and by a variety of other names, was fought in 186 ...

, and in the city of

. The division was disbanded in 1919 during the demobilization of the German Army after

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

Combat chronicle

During the Franco-Prussian War, the 21st Infantry Division fought in the opening Battle of Woerth and the major

Battle of Sedan The Battle of Sedan was fought during the Franco-Prussian War from 1 to 2 September 1870. Resulting in the capture of Emperor Napoleon III and over a hundred thousand troops, it effectively decided the war in favour of Prussia and its allies, ...

. It subsequently participated in the Siege of Paris. In World War I in 1914, the 21st Infantry Division fought in the Allied

Great Retreat The Great Retreat (), also known as the retreat from Mons, was the long withdrawal to the River Marne in August and September 1914 by the British Expeditionary Force (BEF) and the French Fifth Army. The Franco-British forces on the Western Fr ...

, including the

First Battle of the Marne The First Battle of the Marne was a battle of the First World War fought from 5 to 12 September 1914. It was fought in a collection of skirmishes around the Marne River Valley. It resulted in an Entente victory against the German armies in the ...

, and in the

Race to the Sea The Race to the Sea (; , ) took place from about 1914 during the First World War, after the Battle of the Frontiers () and the German advance into France. The invasion had been stopped at the First Battle of the Marne and was followed by the ...

. In 1916, it saw action in the

Battle of Verdun The Battle of Verdun (french: Bataille de Verdun ; german: Schlacht um Verdun ) was fought from 21 February to 18 December 1916 on the Western Front in France. The battle was the longest of the First World War and took place on the hills north ...

and the

Battle of the Somme The Battle of the Somme ( French: Bataille de la Somme), also known as the Somme offensive, was a battle of the First World War fought by the armies of the British Empire and French Third Republic against the German Empire. It took place bet ...

. In 1917, it fought in the

Second Battle of the Aisne The Second Battle of the Aisne (french: Bataille du Chemin des Dames or french: Seconde bataille de l'Aisne, 16 April – mid-May 1917) was the main part of the Nivelle Offensive, a Franco-British attempt to inflict a decisive defeat on the Germa ...

. It served in the German 1918 Spring Offensive, including the

Second Battle of the Somme The Second Battle of the Somme of 1918 was fought during the First World War on the Western Front from late August to early September, in the basin of the River Somme. It was part of a series of successful counter-offensives in response to th ...

. Allied intelligence rated the division as first class.

Order of battle in the Franco-Prussian War

During wartime, the 21st Division, like other regular German divisions, was redesignated an infantry division. The organization of the 21st Infantry Division in 1870 at the beginning of the Franco-Prussian War was as follows: *41. Infanterie-Brigade **Füsilier-Regiment Nr. 34 **Füsilier-Regiment Nr. 80 *42. Infanterie-Brigade **Infanterie-Regiment Nr. 81 **Infanterie-Regiment Nr. 88 *Jäger-Bataillon Nr. 11 *Dragoner-Regiment Nr. 5

Pre-World War I organization

German divisions underwent various organizational changes after the Franco-Prussian War. As noted above, the 21st Division was reorganized to become primarily a Hannover/Brunswick unit. The organization of the 21st Division in 1914, shortly before the outbreak of World War I, was as follows: *41. Infanterie-Brigade: ** 1. Nassauisches Infanterie-Regiment Nr. 87 **2. Nassauisches Infanterie-Regiment Nr. 88 *42.Infanterie-Brigade: **Füsilier-Regiment von Gerdsdorff (1. Kurhessisches) Nr. 80 **Infanterie-Regiment Landgraf Friedrich I. von Hessen-Kassel (1. Kurhessisches) Nr. 81 *21. Kavallerie-Brigade: **Magdeburgisches Dragoner-Regiment Nr. 6 **Thüringisches Ulanen-Regiment Nr. 6Commander in 1903-06
*21. Feldartillerie-Brigade: **1. Nassauisches Feldartillerie-Regiment Nr. 27 **2. Nassauisches Feldartillerie-Regiment Nr. 63

Order of battle on mobilization

On mobilization in August 1914 at the beginning of

, most divisional cavalry, including brigade headquarters, was withdrawn to form cavalry divisions or split up among divisions as reconnaissance units. Divisions received engineer companies and other support units from their higher headquarters. The 21st Division was again renamed the 21st Infantry Division and its initial wartime organization was as follows:Cron et al., ''Ruhmeshalle'' *41. Infanterie-Brigade: **1. Nassauisches Infanterie-Regiment Nr. 87 **2. Nassauisches Infanterie-Regiment Nr. 88 *42.Infanterie-Brigade: **Füsilier-Regiment von Gerdsdorff (1. Kurhessisches) Nr. 80 **Infanterie-Regiment Landgraf Friedrich I. von Hessen-Kassel (1. Kurhessisches) Nr. 81 *Thüringisches Ulanen-Regiment Nr. 6 *21. Feldartillerie-Brigade: **1. Nassauisches Feldartillerie-Regiment Nr. 27 **2. Nassauisches Feldartillerie-Regiment Nr. 63 *1.Kompanie/1. Nassauisches Pionier-Bataillon Nr. 21

Late World War I organization

Divisions underwent many changes during the war, with regiments moving from division to division, and some being destroyed and rebuilt. During the war, most divisions became

triangular A triangle is a polygon with three edges and three vertices. It is one of the basic shapes in geometry. A triangle with vertices ''A'', ''B'', and ''C'' is denoted \triangle ABC. In Euclidean geometry, any three points, when non- collinea ...

- one infantry brigade with three infantry regiments rather than two infantry brigades of two regiments (a "

square division A square division is a designation given to the way military divisions are organized. In a square organization, the division's main body is composed of four "maneuver," i.e., infantry regimental elements. Other types of regiments, such as artillery, ...

"). An artillery commander replaced the artillery brigade headquarters, the cavalry was further reduced, the engineer contingent was increased, and a divisional signals command was created. The 21st Infantry Division's order of battle on April 28, 1918, was as follows: *42. Infanterie-Brigade: **Füsilier-Regiment von Gerdsdorff (1. Kurhessisches) Nr. 80 **Infanterie-Regiment Landgraf Friedrich I. von Hessen-Kassel (1. Kurhessisches) Nr. 81 **1. Nassauisches Infanterie-Regiment Nr. 87 *2.Eskadron/Magdeburgisches Dragoner-Regiment Nr. 6 *Artillerie-Kommandeur 21: **1. Nassauisches Feldartillerie-Regiment Nr. 27 **II.Bataillon/Badisches Fußartillerie-Regiment Nr. 14 (from May 7, 1918) *Stab 1. Nassauisches Pionier-Bataillon Nr. 21: **1.Kompanie/1. Nassauisches Pionier-Bataillon Nr. 21 **5.Kompanie/1. Nassauisches Pionier-Bataillon Nr. 21 **Minenwerfer-Kompanie Nr. 21 *Divisions-Nachrichten-Kommandeur 21

References

21. Infanterie-Division (Chronik 1914/1918) - Der erste Weltkrieg
* Claus von Bredow, bearb., ''Historische Rang- und Stammliste des deutschen Heeres'' (1905) * Hermann Cron et al., ''Ruhmeshalle unserer alten Armee'' (Berlin, 1935) * Hermann Cron, ''Geschichte des deutschen Heeres im Weltkriege 1914-1918'' (Berlin, 1937) * Günter Wegner, ''Stellenbesetzung der deutschen Heere 1815-1939.'' (Biblio Verlag, Osnabrück, 1993), Bd. 1 * ''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'' (1920)

Notes

{{DEFAULTSORT:21 Infantry divisions of Germany in World War I Military units and formations established in 1866 Military units and formations disestablished in 1919 1866 establishments in Prussia