Order of battle for the Battle of the Somme

This is the order of battle for the Battle of the Somme fought from 1 July to 18 November 1916 as one of the main engagements of the First World War. It was fought between mixed French, British and Dominion forces and the German Empire in the Somme River valley in northern France.

British and Dominion forces
In typical British county regiments, the 1st and 2nd Battalions were regular army, the 3rd was the special reserve battalion which did not normally serve overseas but remained at home as the regimental depot and training unit from which replacemetns were sent to the regular battalions. The 4th, 5th and 6th Battalions were normally Territorial Force battalions. Territorial battalions raised second line battalions which would be numbered 2/4th, 2/5th and 2/6th, initially from men who did not volunteer for overseas service. The terms of service in the Territoiral Force meant that men who had signed up on these could not be forced to serve outside the United Kingdom. The number of battalions depended on the recruitment potential of the area from which the battalions were raised (i.e. the Dorsetshire Regiment raised eleven battalions, whilst the London Regiment managed to raise eighty-eight battalions).

Regular Army Divisions were numbered 1st to 8th. "New Army" divisions raised by the Kitchener recruitment drive were numbered 9th to 26th. The 27th to 29th Divisions were Regular Army divisions made up from units recalled from Imperial Garrison Duties. The 30th to 41st were again made up from New Army units while the 42nd to 74th were Territorial. The 63rd Division (Royal Naval Division) was made up from Naval Reserves and did not follow this numbering pattern.

Army structures

 * British Expeditionary Force: Commander: General Sir Douglas Haig
 * Third Army: Army Commander: General Sir Edmund H.H. Allenby
 * Fourth Army: The Fourth Army was formed on 5 February 1916. Army Commander: General Sir Henry Rawlinson.
 * Reserve Army: The Reserve Army was formed on 23 May 1916 and took over VIII and X Corps from the Fourth Army on 4 July 1916 during the Battle of Albert. Army Commander: General Sir Hubert Gough
 * Fifth Army: The Reserve Army was renamed the Fifth Army on 30 October 1916

Corps structures

 * II Corps. Corps Commander: Lieutenant-General Claude W.Jacob
 * III Corps. Corps Commander: Major-General Henry Hudson later replaced by Lieutenant-General Sir William Pulteney
 * V Corps. Corps Commander: Lieutenant-General Edward A. Fanshawe
 * VII Corps. Corps Commander: Lieutenant-General Sir Thomas d'Oyly Snow
 * VIII Corps. Corps Commander: Lieutenant-General Aylmer Hunter-Weston
 * X Corps. Corps Commander: Lieutenant-General Sir Thomas Morland
 * XIII Corps. Corps Commander: Lieutenant-General Walter N. Congreve VC
 * XIV Corps. Corps Commander: Lieutenant-General Rudolph Lambart, 10th Earl of Cavan
 * XV Corps. Corps Commander: Lieutenant General D.M.G. Campbell, then Lt–Gen Henry Horne then Lt–General John du Cane
 * Canadian Corps. Corps Commander: Lieutenant-General the Honourable Sir Julian Byng
 * ANZAC Corps. Corps Commander: Lieutenant-General Sir William Birdwood
 * Machine Gun Corps

French 6th Army Corps, which contained British or Dominion forces:
 * 20th Army Corps (France). The 11th and 39th Divisions were attached to the French XX Corps (French Sixth Army) for the opening days of the Battle.
 * 35th Army Corps (France). The British 2nd Division was detached to XXXV Corps, French 6th Army.

Formations per Battle
Refer following section titled "Divisions" for brigades, regiments and battalions associated with each division participating in the listed battles. Battle nomenclature and participating units information taken from source British Army Council Command Notice 1138 unless stated otherwise:

Battle of Albert: 1–13 July 1916

 * Capture of Montauban
 * Capture of Mametz
 * Capture of Fricourt
 * Capture of Contalmaison
 * Capture of la Boiselle

Battle of Bazentin Ridge: 14–17 July 1916

 * Capture of Longueval
 * Capture of Trônes Wood
 * Capture of Ovillers

Battle of Pozières: 23 July – 3 September 1916

 * Fighting for Mouquet Farm

Battle of Flers-Courcelette: 15–22 September 1916

 * Capture of Martinpuich

Battle of Morval: 25–28 September 1916

 * Capture of Crombles
 * Capture of Lesboeufs
 * Capture of Gueudecourt

Battle of le Transloy: 1–18 October 1916

 * Capture of Eaucourt l'Abbaye
 * Capture of le Sars
 * Attacks on the Butte de Warlencourt

Battle of Ancre Heights: 1–18 October 1916

 * Capture of Schwaben Redoubt
 * Capture of Stuff Redoubt
 * Capture of Regina Trench

Battle of the Ancre: 13–16 November 1916

 * Capture of Beaumont Hamel

Royal Flying Corps

 * No. 1 Squadron RFC
 * No. 2 Squadron RFC
 * No. 3 Squadron RFC
 * No. 4 Squadron RFC
 * No. 6 Squadron RFC
 * No. 9 Squadron RFC
 * No. 10 Squadron RFC
 * No. 41 Squadron RFC
 * No. 70 Squadron RFC

French forces
A majority of the French Divisions were triangular divisions – that is comprising three regiments, with each regiment containing three battalions.

During the Battle of Verdun, General Pétain had rotated the French Divisions through the battle – resulting in a large number of divisions entering the battle with experience.

Army and Corps organisation
List of Army/Corp/Divisions involved taken from Organigramme des Grandes Batailles.

Army structures

 * Northern Army Group (Groupe d'armées du Nord): Commander: General Ferdinand Foch
 * Sixth Army: Army Commander: General Marie Émile Fayolle
 * Tenth Army: Army Commander: General Joseph Alfred Micheler

Corps structures
(Note: That a majority of the Corps/Divisions were rotated in from other Armies as the battle progressed.)
 * I Corps. Corps Commander: General Adolphe Guillaumat
 * II Corps. Corps Commander: General Denis Auguste Duchêne
 * V Corps. Corps Commander: General Antoine Baucheron de Boissoudy
 * VI Corps. Corps Commander: General Marie Jean Auguste Paulinier
 * VII Corps. Corps Commander: General Georges de Bazelaire
 * IX Corps. Corps Commander: General Horace Fernand Achille Pentel
 * XI Corps. Corps Commander: General Charles Mangin
 * XX Corps. Corps Commander: Generals Georges Prosper Anne Claret de la Touche and Émile Alexis Mazillier
 * XXI Corps. Corps Commander: General Paul Maistre
 * XXX Corps. Corps Commander: General Paul Chrétien
 * XXXII Corps. Corps Commander: Generals Henri Mathias Berthelot and Marie-Eugène Debeney
 * XXXIII Corps. Corps Commander: General Alphonse Nudant
 * XXXV Corps. Corps Commander: General Charles Jacquot
 * I Colonial Corps. Corps Commander: General Pierre Berdoulat
 * II Colonial Corps. Corps Commander: General Ernest Blondlat
 * I Cavalry Corps. Corps Commander: General Louis Conneau
 * II Cavalry Corps. Corps Commander: General Antoine de Mitry

Infantry Divisions
1st Infantry Division 2nd Infantry Division 3rd Infantry Division 4th Infantry Division 10th Infantry Division 11th Infantry Division 12th Infantry Division 13th Infantry Division 14th Infantry Division 17th Infantry Division 18th Infantry Division 20th Infantry Division 25th Infantry Division 26th Infantry Division 39th Infantry Division 41st Infantry Division 42nd Infantry Division 43rd Infantry Division 45th Infantry Division 46th Infantry Division 47th Infantry Division 48th Infantry Division 51st Infantry Division 53rd Infantry Division 56th Infantry Division 61st Infantry Division 62nd Infantry Division 66th Infantry Division 70th Infantry Division 72nd Infantry Division 77th Infantry Division 120th Infantry Division 121st Infantry Division 125th Infantry Division 127th Infantry Division 132nd Infantry Division 152nd Infantry Division 153rd Infantry Division Moroccan Infantry Division 2nd Colonial Infantry Division 3rd Colonial Infantry Division 10th Colonial Infantry Division 15th Colonial Infantry Division 16th Colonial Infantry Division

Cavalry Divisions
1st Cavalry Division 2nd Cavalry Division 3rd Cavalry Division 4th Cavalry Division

German Forces: 2nd Army
All German order of battle derived from Hart, Appendix C unless stated otherwise. German Army Group Commander: von Gallwitz Commander: General der Infanterie Fritz von Below Chiefs of Staff: General Erich Falkenhayn (until 28 August 1916), General Paul von Hindenburg

At this time, German Divisions were in the process of being converted from square to triangular, hence some had four infantry regiments, others had three.