# IX Reserve Corps (German Empire)

The IX Reserve Corps (German: IX. Reserve-Korps / IX RK) was a corps level command of the German Army in World War I.

## Formation

IX Reserve Corps was formed on the outbreak of the war in August 1914 as part of the mobilisation of the Army. It was initially commanded by General der Infanterie Max von Boehn, brought out of retirement. It was still in existence at the end of the war in the 5th Army, Heeresgruppe Gallwitz on the Western Front.

### Structure on formation

On formation in August 1914, IX Reserve Corps consisted of two divisions, made up of reserve units. In general, Reserve Corps and Reserve Divisions were weaker than their active counterparts
    Reserve Infantry Regiments did not always have three battalions nor necessarily contain a machine gun company
    Reserve Jäger Battalions did not have a machine gun company on formation
    Reserve Cavalry Regiments consisted of just three squadrons
    Reserve Field Artillery Regiments usually consisted of two abteilungen of three batteries each
    Corps Troops generally consisted of a Telephone Detachment and four sections of munition columns and trains
The IX Reserve Corps was exceptional as it formed the major part of the North Army so was provided with more Corps Troops than other Reserve Corps: a Foot Artillery Battalion, a Pioneer Regiment and a Field Airship Detachment.
In summary, IX Reserve Corps mobilised with 25 infantry battalions, 5 machine gun companies (30 machine guns), 6 cavalry squadrons, 12 field artillery batteries (72 guns), 4 heavy batteries (16 guns), a Field Airship Detachment and 7 pioneer companies. 17th Reserve Division was slightly stronger than the norm as it included an active infantry brigade.
| Corps | Division | Brigade | Units |
| IX Reserve Corps | 17th Reserve Division | 81st Infantry Brigade | 162nd Infantry Regiment |
| IX Reserve Corps | 17th Reserve Division | 81st Infantry Brigade | 163rd Infantry Regiment |
| IX Reserve Corps | 17th Reserve Division | 33rd Reserve Infantry Brigade | 75th Reserve Infantry Regiment |
| IX Reserve Corps | 17th Reserve Division | 33rd Reserve Infantry Brigade | 76th Reserve Infantry Regiment |
| IX Reserve Corps | 17th Reserve Division | | 6th Reserve Hussar Regiment |
| IX Reserve Corps | 17th Reserve Division | | 17th Reserve Field Artillery Regiment |
| IX Reserve Corps | 17th Reserve Division | | 4th Company, 9th Pioneer Battalion |
| IX Reserve Corps | 17th Reserve Division | | 17th Reserve Divisional Pontoon Train |
| IX Reserve Corps | 17th Reserve Division | | 9th Reserve Medical Company |
| IX Reserve Corps | 18th Reserve Division | 34th Reserve Infantry Brigade | 31st Reserve Infantry Regiment |
| IX Reserve Corps | 18th Reserve Division | 34th Reserve Infantry Brigade | 90th Reserve Infantry Regiment |
| IX Reserve Corps | 18th Reserve Division | 35th Reserve Infantry Brigade | 84th Reserve Infantry Regiment |
| IX Reserve Corps | 18th Reserve Division | 35th Reserve Infantry Brigade | 86th Reserve Infantry Regiment |
| IX Reserve Corps | 18th Reserve Division | 35th Reserve Infantry Brigade | 9th Reserve Jäger Battalion |
| IX Reserve Corps | 18th Reserve Division | | 7th Reserve Hussar Regiment |
| IX Reserve Corps | 18th Reserve Division | | 18th Reserve Field Artillery Regiment |
| IX Reserve Corps | 18th Reserve Division | | 1st Reserve Company, 9th Pioneer Battalion |
| IX Reserve Corps | 18th Reserve Division | | 2nd Reserve Company, 9th Pioneer Battalion |
| IX Reserve Corps | 18th Reserve Division | | 13th Reserve Medical Company |
| IX Reserve Corps | Corps Troops | | II Battalion, 2nd Guards Foot Artillery Regiment |
| IX Reserve Corps | Corps Troops | | 31st Pioneer Regiment |
| IX Reserve Corps | Corps Troops | | 9th Reserve Telephone Detachment |
| IX Reserve Corps | Corps Troops | | 5th Field Airship Detachment |
| IX Reserve Corps | Corps Troops | | Munition Trains and Columns corresponding to the III Reserve Corps |

## Combat chronicle

On mobilisation, IX Reserve Corps was assigned to the North Army, which was held back in Schleswig to defend the German North Sea Coast in case of British landings. It was soon transferred to the Western Front, joining 1st Army in late August.

## Commanders

IX Reserve Corps had the following commanders during its existence:
| From | Rank | Name |
| 2 August 1914 | General der Infanterie | Max von Boehn |
| 2 February 1917 | Generalleutnant | Viktor Kühne |
| 12 March 1917 | Generalleutnant | Karl Dieffenbach |