Organization of an Infantry Regiment
1914
In 1914, there were 173 active regiments of line infantry (1 to 173). These were generally comprised of three battalions (save for nine regiments which had four battalions: 69, 157, 159, 163 to 166, 170, 173). The battalions -- composed of 4 companies each -- were numbered 1st (1st to 4th Company), 2nd (5th to 8th Company), and 3rd (9th to 12th Company). Each active regiment was supplemented with a corresponding reserve regiment consisting two battalions. These reserve regiments took the number of their parent active regiment, plus 200 (thus, 201 to 373). Thus, in total there were 346 infantry regiments (units dissolved during the course of the war are covered separately here). The battalions of the reserve regiments were numbered 5th (17th to 20th Company) and 6th (21st to 24th Company). The reserve regiments did not stay attached to its active sister unit but were mostly brigaded into reserve divisions. Others were used as reserve for active army corps (usually two in each corps). Lastly, there were 145 (1 to 145) territorial regiments and 148 reserve territorial regiments (201 to 347, 500, 501). Territorial units were composed of three or more battalions -- one for each region subdivision. Most remained in their respective military subdivisons, though some were incorporated into territorial divisions.
Up to 1914, the power of the infantry was counted in the number of rifles it possessed. At the opening of the war, the vast majority of battalions were made up of 4 companies of about 250 effectives, comprising around 1,000 rifles. There was only one machine-gun section (with 2 guns) for each battalion. However, this was put not at the discretion of the battalion leader but the corps commander.
Aside from the ranks of each battalion, there were additional units within the regiment. Unit command was comprised of the regimental general-staff along with a small-staff for each battalion. There was also the out-of-ranks company (i.e. HQ company), and the regimental supply train and combat train. These brought the total theoretical effective of an infantry regiment to 3,250 men and officers.
Number of Effectives in 1914 (full strength)
Regiment: 3,250*
Battalion: 1,000
Company: 250
Weapons Ratio of a Regiment: 3,000 rifles, 6 machine-guns.
*Note: Of this number, about 2,750 (or 92%) could be considered true combat effectives.
August 1914
Regiment (active)3 Battalions and 1 HQ Company
Company (4 sections) Section (4 squads)
2 Battalions and 1 HQ Company
Company (4 sections) Section (4 squads)
1915
At the start of 1915, three new regiments (174 to 176) were created, two of which were sent to the foreign theaters (the Dardanelles in Turkey and Salonika in Greece and Macedonia). Another twenty (401 to 421) were created primarily in March and April (six were formed from August-September). The numerical designation was attained by adding 400 to the army corps region number where the regiment was based (with the exception of the 419 RI). These regiments were detached from the other regiments of their respective army-corps and were composed almost entirely of new recruits (class of 1915 and '16) and returning wounded vets. In June, following the massacre of certain units, thirty-three new divisions were created: 120 to 134, 151 to 158, and 161 to 170.
However, beginning in 1915 -- in the face of unsustainable losses -- the number of men comprising a company was gradually reduced from 250 to 200 effectives. Also, the number of men comprising a battalion was reduced from 1,000 to 750 effectives (achieved by removing the fourth company from each battalion). The distinction between the active and reserve regiments was formally erased in 1915 and the reserve regiment became entirely autonomous from its active sister. The two-battalion organization of reserve regiments would still remain in place for the time being. Detachments of grenadiers were created at the company level: 16 men with 1 NCO at the head. Eight of these men (with 1 corporal) were trained as bombadiers, utilizing an array of light trench engines (mortars, catapults, cross-bows, etc.). Meanwhile, the number of machine-gun sections was increased to four (8 guns total) per regiment and reorganized into an autonomous company.
Number of Effectives in 1915 (full strength)
Regiment: 2,750
Battalion: 800
Company: 200
Weapons Ratio of a Regiment: 2,400 rifles, 8 machine-guns, small group of light trench engines.
December 1915
Regiment3 Battalions, 1 HQ Company and 1 MG Company
Company (4 sections) Section (2 half-sections) Half-section (2 squads)
1916-17
In 1916, shortages in manpower led to the disbandment in the spring of six of the new regiments that had been created in 1915 (402, 405, 406, 419 to 421), along with the disbandment of two reserve regiments from each reserve division (seventeen in total) from the spring to summer. In both cases, the remaining men were transferred to other regiments.
Organizationally, the brigade is gradually phased out of existence in 1916. In certain reserve regiments, a third battalion is added (numbered the 4th) to bring them more into line with the structure of the active regiments. The company was also reorganized into two separate half-sections, each made up of two squads. Two additional machine-gun companies were created, bringing to the total to three per regiment and eventually replacing the fourth riflemen company altogether. Additionally, each regiment was given three 37 mm guns (with one going to each battalion), along with several trench mortars (notably, the Brandt pneumatic).
Number of Effectives in 1916 (full strength)
Regiment: ~2,500
Battalion: 800
Company: 200
Weapons Ratio of a Regiment: 1,800 rifles, 24 machine-guns, 72 automatic-rifles, 144 VB launchers, 3 37 mm guns, assortment of trench mortars.
April 1916 to December 1917
Regiment3 Battalions, 1 HQ Company and 3 MG Companies
Company (4 sections and 1 MG section) Section (2 half-sections) Half-Section (4 squads)
1917-18
In the summer and fall of 1917, twenty-one reserve regiments are disbanded with the majority of the remaining men mostly being transferred to other reserve units, along with some who were transferred to active ones. A smaller number were mustered out of service completely. On the organizational level, the company is further strengthened with the addition of an automatic-rifle (kept in reserve) placed within each half-section. Also, six more VB launchers are distributed within each half-section. At the end of the year, a section of Stokes mortars (2) is created at the regiment level.
In the summer and fall of 1918, another sixteen reserve regiments were disbanded, the majority of men again being transferred to other reserve units (though several of the regiments disbanded had simply been annihilated). Additionally, the number of Stokes mortars (per mortar section) is increased to six.
Number of Effectives in 1917 (When at Full Strength)
Regiment: ~2,500
Battalion: 800
Company: 200
Weapons Ratio of a Regiment: 1,800 rifles, 36 machine-guns, 108 automatic-rifles, 576 VB launchers, 3 37 mm guns, assortment of trench mortars.
December 1917 to November 1918
Regiment3 Battalions, 1 HQ Company and 3 Machine-Gun Companies
Company (4 sections and 1 MG section) Section (2 half-sections) Half-Section (4 squads)
Sources:
Bouchery, P. and F. Vauvillier. "1916, Le Poilu de Verdun." Militaria Magazine no. 39 (Nov. 1998) .
British General Staff, ed. Handbook of the French Army, 1914. Battery Press: Nashville, 2002.
British General Staff, ed. French Trench Warfare, 1917-1918: A Reference Manual. Battery Press: Nashville, 2002.
Sheffield, Gary, ed. War on the Western Front: In the Trenches of World War I. Osprey Publishing: Oxford, 2007.
Sumner, Ian and Gerry Embleton. The French Army 1914-1918. Osprey Publishing: Oxford, 1999.
Vauvillier, François. Nos Poilus de 1914-1918: L'Infanterie. Histoire & Collections: Paris, 2006.
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