# IX Corps (German Empire)

The IX Army Corps / IX AK (German: IX. Armee-Korps) was a corps level command of the Prussian and German Armies before and during World War I.
IX Corps was one of three formed in the aftermath of the Austro-Prussian War (the others being X Corps and XI Corps). The Corps was formed in October 1866 with headquarters in Altona. The catchment area included the newly annexed Province of Schleswig-Holstein, the Grand Duchies of Mecklenburg-Schwerin and Mecklenburg-Strelitz and the Hanseatic cities of Lübeck, Hamburg and Bremen.
During the Franco-Prussian War it was assigned to the 2nd Army.
The Corps was assigned to the III Army Inspectorate but joined the 1st Army at the start of the First World War. It was still in existence at the end of the war. The Corps was disbanded with the demobilisation of the German Army after World War I.

## Franco-Prussian War

During the Franco-Prussian War, the corps formed part of the 2nd Army. The 17th Division was initially part of the reserve of the Prussian Army, so the 18th Division was joined by the Grand Ducal Hessian (25th) Division. The Corps participated in the battles of Gravelotte, Orléans and Le Mans.

## Flags of the Line Infantry regiments

Due to the large number of Line Infantry regiments then in existence, on 18 December 1890, Kaiser Wilhelm II ordered that the flag colours were to be the same as that of the uniform epaulettes. This was to ensure that each corps attained uniformity. IX and X Corps wore white epaulettes. Notwithstanding this, the flags of the Jäger Battalions would be green.
| Flag of the Line Infantry regiments of the IX and X Corps (except Jägers) | Flag of the Jägers Battalion |

## 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. 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 Corps 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).
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 :
| Corps | Division | Brigade | Units | Garrison |
| IX Corps | 17th Division | 33rd Infantry Brigade | 75th (1st Hanseatic)(Bremen) Infantry | Bremen, III Bn at Stade |
| IX Corps | 17th Division | 33rd Infantry Brigade | 76th (2nd Hanseatic)(Hamburg) Infantry | Hamburg |
| IX Corps | 17th Division | 34th Infantry Brigade | 89th (Grand Ducal Mecklenburgian) Grenadiers | Schwerin, II Bn at Neustrelitz |
| IX Corps | 17th Division | 34th Infantry Brigade | 90th (Grand Ducal Mecklenburgian) Fusiliers "Emperor William" | Rostock, II Bn at Wismar |
| IX Corps | 17th Division | 81st Infantry Brigade | 162nd (3rd Hanseatic)(Lübeck) Infantry | Lübeck, II Bn at Eutin |
| IX Corps | 17th Division | 81st Infantry Brigade | 163rd (Schleswig-Holstein) Infantry | Neumünster, III Bn at Heide |
| IX Corps | 17th Division | 17th Field Artillery Brigade | 24th (Holstein) Field Artillery | Güstrow, Neustrelitz |
| IX Corps | 17th Division | 17th Field Artillery Brigade | 60th (Grand Ducal Mecklenburgian) Field Artillery | Schwerin |
| IX Corps | 17th Division | 17th Cavalry Brigade | 17th (1st Grand Ducal Mecklenburgian) Dragoons | Ludwigslust |
| IX Corps | 17th Division | 17th Cavalry Brigade | 18th (2nd Grand Ducal Mecklenburgian) Dragoons | Parchim |
| IX Corps | 18th Division | 35th Infantry Brigade | 84th (Schleswig) Infantry "von Manstein" | Schleswig, Hadersleben |
| IX Corps | 18th Division | 35th Infantry Brigade | 86th (Schleswig-Holstein) Fusiliers "Queen" | Flensburg, III Bn at Sonderburg |
| IX Corps | 18th Division | 36th Infantry Brigade | 31st (1st Thuringian) Infantry "Count Bose" | Altona |
| IX Corps | 18th Division | 36th Infantry Brigade | 85th (Holstein) Infantry "Duke of Holstein" | Rendsburg, III Bn at Kiel |
| IX Corps | 18th Division | 18th Field Artillery Brigade | 9th (Schleswig) Field Artillery "General Field Marshal Graf Waldersee" | Itzehoe |
| IX Corps | 18th Division | 18th Field Artillery Brigade | 45th (Lauenburg) Field Artillery | Altona, Rendsburg |
| IX Corps | 18th Division | 18th Cavalry Brigade | 15th (Hannover) Hussars "Queen Wilhelmina of the Netherlands" | Wandsbek |
| IX Corps | 18th Division | 18th Cavalry Brigade | 16th (Schleswig-Holstein) Hussars "Emperor Francis Joseph of Austria, King of Hungary" | Schleswig |
| IX Corps | Corps Troops | | 9th (Lauenburg) Jäger Battalion | Ratzeburg |
| IX Corps | Corps Troops | | 20th (Lauenburg) Foot Artillery | Altona |
| IX Corps | Corps Troops | | 9th (Schleswig-Holstein) Pioneer Battalion | Harburg |
| IX Corps | Corps Troops | | 9th (Schleswig-Holstein) Train Battalion | Rendsburg |
| IX Corps | Altona Defence Command (Landwehr-Inspektion) | | | Altona |

## World War I
### Organisation on mobilisation

On mobilization on 2 August 1914 the Corps was restructured. 17th and 18th Cavalry Brigades were withdrawn to form part of the 4th Cavalry Division. The 16th Dragoons, formerly of the X Corps, was raised to a strength of 6 squadrons before being split into two half-regiments of 3 squadrons each. The half-regiments were assigned as divisional cavalry to 17th and 18th Divisions. 81st Infantry Brigade was transferred to 17th Reserve Division in IX Reserve Corps. Divisions received engineer companies and other support units from the Corps headquarters. In summary, IX Corps mobilised with 25 infantry battalions, 9 machine gun companies (54 machine guns), 6 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 :
| Corps | Division | Brigade | Units |
| IX Corps | 17th Division | 33rd Infantry Brigade | 75th Infantry Regiment |
| IX Corps | 17th Division | 33rd Infantry Brigade | 76th Infantry Regiment |
| IX Corps | 17th Division | 34th Infantry Brigade | 89th Grenadier Regiment |
| IX Corps | 17th Division | 34th Infantry Brigade | 90th Fusilier Regiment |
| IX Corps | 17th Division | 34th Infantry Brigade | 9th Jäger Battalion |
| IX Corps | 17th Division | 17th Field Artillery Brigade | 24th Field Artillery Regiment |
| IX Corps | 17th Division | 17th Field Artillery Brigade | 60th Field Artillery Regiment |
| IX Corps | 17th Division | | staff and half of 16th Dragoon Regiment |
| IX Corps | 17th Division | | 1st Company, 9th Pioneer Battalion |
| IX Corps | 17th Division | | 17th Divisional Pontoon Train |
| IX Corps | 17th Division | | 1st Medical Company |
| IX Corps | 17th Division | | 3rd Medical Company |
| IX Corps | 18th Division | 35th Infantry Brigade | 84th Infantry Regiment |
| IX Corps | 18th Division | 35th Infantry Brigade | 86th Fusilier Regiment |
| IX Corps | 18th Division | 36th Infantry Brigade | 31st Infantry Regiment |
| IX Corps | 18th Division | 36th Infantry Brigade | 85th Infantry Regiment |
| IX Corps | 18th Division | 18th Field Artillery Brigade | 9th Field Artillery Regiment |
| IX Corps | 18th Division | 18th Field Artillery Brigade | 45th Field Artillery Regiment |
| IX Corps | 18th Division | | half of 16th Dragoon Regiment |
| IX Corps | 18th Division | | 2nd Company, 9th Pioneer Battalion |
| IX Corps | 18th Division | | 3rd Company, 9th Pioneer Battalion |
| IX Corps | 18th Division | | 18th Divisional Pontoon Train |
| IX Corps | 18th Division | | 2nd Medical Company |
| IX Corps | Corps Troops | | I Battalion, 20th Foot Artillery Regiment |
| IX Corps | Corps Troops | | 11th Aviation Detachment |
| IX Corps | Corps Troops | | 9th Corps Pontoon Train |
| IX Corps | Corps Troops | | 9th Telephone Detachment |
| IX Corps | Corps Troops | | 9th Pioneer Searchlight Section |
| IX Corps | Corps Troops | | Munition Trains and Columns corresponding to II Corps |

### Combat chronicle

On mobilisation, IX Corps was assigned to the 1st Army on the right wing of the forces for the Schlieffen Plan offensive in August 1914 on the Western Front. It participated in the Battle of Mons and the First Battle of the Marne which marked the end of the German advances in 1914. Later it saw action in the Battle of Pozières and Battle of Amiens (1918).
It was still in existence at the end of the war.

## Commanders

The IX Corps had the following commanders during its existence:
| From | Rank | Name |
| 30 October 1866 | General der Infanterie | Edwin Freiherr von Manteuffel |
| 26 January 1867 | General der Infanterie | Albrecht Gustav von Manstein |
| 23 September 1873 | General der Infanterie | Hermann von Tresckow |
| 2 August 1888 | General der Infanterie | Paul von Leszczynski |
| 2 February 1891 | General der Kavallerie | Alfred Graf von Waldersee |
| 5 April 1898 | General der Kavallerie | Robert von Massow |
| 29 October 1903 | Generalleutnant | Friedrich von Bock und Polach |
| 21 May 1907 | General der Kavallerie | Hermann Freiherr von Vietinghoff genannt Scheel |
| 12 April 1910 | General der Infanterie | Karl Freiherr von Plettenberg |
| 1 March 1913 | General der Infanterie | Ferdinand von Quast |
| 24 January 1917 | Generalleutnant | Horst Ritter und Edler von Oetinger |