# I Reserve Corps (German Empire)

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

## Formation

I 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 Generalleutnant Otto von Below. It was still in existence at the end of the war in the 3rd Army, Heeresgruppe Deutscher Kronprinz on the Western Front.

### Structure on formation

On formation in August 1914, I 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
In summary, I Reserve Corps mobilised with 26 infantry battalions, 11 machine gun companies (66 machine guns), 6 cavalry squadrons, 12 field artillery batteries (72 guns) and 2 pioneer companies. 1st Reserve Division was particularly strong in machine gun formations as the 1st, 3rd and 18th Reserve Infantry Regiments all had two machine gun companies. 36th Reserve Division was formed by units drawn from the XVII Corps District. It included one active Infantry Regiment (54th).
| Corps | Division | Brigade | Units |
| I Reserve Corps | 1st Reserve Division | 1st Reserve Infantry Brigade | 1st Reserve Infantry Regiment |
| I Reserve Corps | 1st Reserve Division | 1st Reserve Infantry Brigade | 3rd Reserve Infantry Regiment |
| I Reserve Corps | 1st Reserve Division | 42nd Reserve Infantry Brigade | 18th Reserve Infantry Regiment |
| I Reserve Corps | 1st Reserve Division | 42nd Reserve Infantry Brigade | 59th Reserve Infantry Regiment |
| I Reserve Corps | 1st Reserve Division | 42nd Reserve Infantry Brigade | 1st Reserve Jäger Battalion |
| I Reserve Corps | 1st Reserve Division | | 1st Reserve Uhlan Regiment |
| I Reserve Corps | 1st Reserve Division | | 1st Reserve Field Artillery Regiment |
| I Reserve Corps | 1st Reserve Division | | 4th Company, 2nd Pioneer Battalion |
| I Reserve Corps | 1st Reserve Division | | 1st Reserve Divisional Pontoon Train |
| I Reserve Corps | 1st Reserve Division | | 1st Reserve Medical Company |
| I Reserve Corps | 36th Reserve Division | 69th Reserve Infantry Brigade | 21st Reserve Infantry Regiment |
| I Reserve Corps | 36th Reserve Division | 69th Reserve Infantry Brigade | 61st Reserve Infantry Regiment |
| I Reserve Corps | 36th Reserve Division | 69th Reserve Infantry Brigade | 2nd Reserve Jäger Battalion |
| I Reserve Corps | 36th Reserve Division | 70th Reserve Infantry Brigade | 54th Infantry Regiment |
| I Reserve Corps | 36th Reserve Division | 70th Reserve Infantry Brigade | 5th Reserve Infantry Regiment |
| I Reserve Corps | 36th Reserve Division | | 1st Reserve Hussar Regiment |
| I Reserve Corps | 36th Reserve Division | | 36th Reserve Field Artillery Regiment |
| I Reserve Corps | 36th Reserve Division | | 1st Reserve Company, 2nd Pioneer Battalion |
| I Reserve Corps | 36th Reserve Division | | 36th Reserve Divisional Pontoon Train |
| I Reserve Corps | 36th Reserve Division | | 15th Reserve Medical Company |
| I Reserve Corps | Corps Troops | | 1st Reserve Telephone Detachment |
| I Reserve Corps | Corps Troops | | Munition Trains and Columns corresponding to the III Reserve Corps |

## Combat chronicle

On mobilisation, I Reserve Corps was assigned to the 8th Army on the Eastern Front, intended to defend East Prussia while the rest of the German Army executed the Schlieffen Plan offensive against France.

## Commanders

I Reserve Corps had the following commanders during its existence:
| From | Rank | Name |
| 2 August 1914 | Generalleutnant | Otto von Below |
| 30 August 1914 | General der Infanterie | Otto von Below |
| 28 November 1914 | Generalleutnant | Kurt von Morgen |
| 24 August 1918 | Generalleutnant | Richard Wellmann |