Mobilization 7 Mobilization of Reserve Units in 1914
Infantry reserve regiments (Reserve Infanterie Regimenter–RIR) were mobilized from reserve personnel who had completed their training and service with the active army—men 22-26 years old and of first contingent Landwehr personnel—men 27-31 years old. Depending on the availability of manpower from these two sources, the composition of reserve formations varied for different RIRs. On average 36-60 percent were reservists. After completing their service within their regiments, they were usually drafted to a reserve exercise within the same formation the following year. During the first year they were administered by the Bezirks-Kommando, but assigned to their regiments. Reservistenbilder were mostly taken at the end of this first reserve exercise. After 1900, their photographs were taken at the end of active service and not at the end of the first reserve exercise, which would seem to indicate that reservists were no longer assigned to their “old” regiments, not even during the first exercise.
The reservists were then administered by the Landwehr-Bezirkskommando of their hometowns or home regions and were assigned to different reserve formations. The reserve and Landwehr formations that mobilized in 1914 were usually made up of men who had neither trained nor exercised together. Although the reservists were called up every year to reserve exercises by their Landwehr-Bezirkskommando, they were usually not called to their “old” regiments, but to other formations—usually these were improvised reserve regiments just assembled for those exercises and maneuvers.
The Landwehr-Bezirkskommando assigned 39-62 percent from first contingent Landwehr to their respective reserve formation. About one to one and one half percent of each reserve unit were active soldiers who came from active formations mobilized at the same time as the reserve formations. Upon mobilization, the active regiments were brought up to war strength by mobilizing reservists, i.e., infantry companies, for example, were increased from 150 to 250 men. This meant that after mobilization, 50 percent of the active regiments were made up of reserve soldiers. Additionally, many officers and NCOs of active regiments were sent to reserve formations during mobilization to provide a stable and experienced framework; their ranks in the active regiments were filled with reserve officers and reserve NCOs. Half of the company and platoon commanders in reserve formations were active duty officers; all battalion commanders and regimental commanders were active officers. Most NCOs were active duty NCOs.
In short, the active line formations contained more than 50 percent reservists after mobilization. Reserve formations comprised a smaller proportion of reservists and a larger share of first contingent Landwehr reservists. Landwehr formations were only allocated second contingent Landwehr reservists. The War Ministry feared that the number of reserve formations was too high and the share of first and second contingent Landwehr reservists too great to create units with a high level of combat effectiveness. In 1899, War Minister v. Goßler wrote an aide memoire to Schlieffen complaining about the loss of quality in active and reserve formations upon mobilization. War Minister v. Einem continued this position after 1903, and frequently opposed demands of the General Staff to build-up further active and reserve formations.
In 1914, after the war started, 113 reserve regiments were mobilized. These were already assigned to their corps in the mobilization calendar (Mobilmachungsplan). For administrative purposes, the reserve regiments were usually allocated the same regimental numbers as the respective active regiments (e.g., Infantry Regiment 118 and Reserve Infantry Regiment 118). This was not usually a case of active parent regiments and reserve dependent regiments. This numbering was purely for administrative purposes. Active regiments within the Landwehr–Bezirk provided the cadre personnel. The active regiments also provided arms and clothing. Artillery depots—depots storing weapons were generally called Artilleriedepots, even if storing only small arms—and garment depots could also provide arms and clothing. The active formation only supported the mobilization with administrative personnel. Within the Guard Corps, in addition to the Guard reserve formations, two line (non Guard) reserve formations (Reserve Infantry Regiment 64 and Reserve Infantry Regiment 93) were mobilized and then assigned to the III and IV Reserve Corps.
Just like active regiments, the reserve regiments were mobilized on the first mobilization day (2 August 1914). Two reserve regiments were assembled in a reserve brigade area and then grouped, first into reserve divisions and then reserve corps. Reserve corps mobilized in August 1914 usually had the following structure after mobilization:
The most significant difference between active formations and reserve formations lay in the quality of equipment in the active corps: artillery, particularly heavy artillery, train units, and supply columns. Active corps were usually equipped with four artillery regiments, totaling 18 batteries of field-guns Model 96, and six batteries of field-howitzers Model 98, while reserve corps usually had only two reserve artillery regiments with a total of 12 batteries of field-guns Model 96. There were no field howitzers to use against entrenchments. Active corps usually had one battalion (four batteries) of heavy artillery attached from their army corps. Very few active and reserve artillery regiments contained three battalions in 1914. With less than half the artillery firepower of an active corps, a reserve corps had a significant tactical deficit that would be keenly felt when fighting against entrenched positions during the 1914 campaigns
Another significant difference was the lack of the corps bridging equipment (Korps-Brückentrain) allocated to each active army corps. Cavalry divisions assembled only upon mobilization and merged into cavalry HKK (Höherer Kavallerie-Kommandeur (HKK)).