The Division was a formation created by the establishment of the Territorial Force in 1908. The Divisional infantry was entirely composed of battalions of the London Regiment. Many of the Division's original units were detached for garrison duties overseas or as reinforcements for other Divisions in the field from late 1914 onward. The entire Divisional artillery was transferred to the 36th (Ulster) Division. The complete Division was reformed in France from 5th January 1916, and served with distinction on the Western Front throughout the rest of the war.

The Attack on the Gommecourt Salient (first phase of the Battle of the Somme 1916)

The Battle of Ginchy (fifth phase of the Battle of the Somme)

The Battle of Flers-Courcelette (sixth phase of the Battle of the Somme 1916)

The Battle of Morval (seventh phase of the Battle of the Somme 1916)

In the above action, the Division captured Combles

The Battle of Le Transloy (eighth phase of the Battle of the Somme 1916)

The German Retreat to the Hindenburg Line

The First Battle of the Scarpe (first phase of the Arras Offensive)

The Third Battle of the Scarpe (fourth phase of the Arras Offensive)

The Battle of Langemarck (second phase of Third Battle of Ypres)

The Battle of Cambrai

The First Battle of Arras, 1918 (fourth phase of the Battles of the Somme 1918)

The Battle of Albert (first phase of the Second Battles of the Somme 1918)

The Battle of the Scarpe (first phase of the Second Battles of Arras 1918)

The Battle of the Canal du Nord (third phase of the Battles of the Hindenburg Line)

The Battle of Cambrai 1918 (sixth phase of the Battles of the Hindenburg Line)

The Pursuit to the Selle

The Battle of the Sambre

The Passage of the Grand Honelle

In all, the Division existed as such for 1010 days during the Great War; it spent 330 days at rest, 195 in quiet sectors, 385 in active sectors and 100 days in battle. Initially selected to join the Army of Occupation on the Rhine, the orders were eventually cancelled and the Division was demobilised. The final cadre returned to England in May 1919.

167th (1st London) Brigade

This Brigade left the Division and moved to Malta in September 1914, and returned to England in February 1915

1/7th Bn, the Middlesex (joined February 1916)

1/8th Bn, the Middlesex (joined February 1916)

4th (Extra Reserve) Bn, the North Staffords(joined October 1917, left November 1917)

1/1st (City of London) Bn, the London Regiment (joined August 1914, left May 1915, rejoined February 1916)

1/2nd (City of London) Bn, the London Regiment (joined August 1914, left February 1915)

1/3rd (City of London) Bn, the London Regiment (joined August 1914, left February 1915, rejoined February 1916, left January 1918)

1/4th (City of London) Bn, the London Regiment (joined August 1914, left February 1915, rejoined November 1915, left February 1916)

167th Brigade Machine Gun Company (formed 22 March 1916, moved into 56 MG Bn 1 March 1918)

167th Trench Mortar Battery (joined 14 June 1916)

168th (2nd London) Brigade

1/4th (City of London) Bn, the London Regiment (joined February 1916)

1/5th (City of London) Bn, the London Regiment (joined August 1914, left November 1914)

1/6th (City of London) Bn, the London Regiment (joined August 1914, left November 1914)

1/7th (City of London) Bn, the London Regiment (joined August 1914, left November 1914)

1/8th (City of London) Bn, the London Regiment (joined August 1914, left November 1914)

1/12th (County of London) Bn, the London Regiment (joined February 1916, left January 1918)

13th (County of London) Bn, the London Regiment (joined February 1916)

1/14th (County of London) Bn, the London Regiment (joined February 1916)

168th Brigade Machine Gun Company (formed 16 March 1916, moved into 56 MG Bn 1 March 1918)

168th Trench Mortar Battery (joined 13 June 1916)

169th (3rd London) Brigade

1/2nd (City of London) Bn, the London Regiment (joined February 1916)

1/5th (City of London) Bn, the London Regiment (joined February 1916)

1/9th (City of London) Bn, the London Regiment (joined August 1914, left November 1914, rejoined February 1916, left February 1918)

1/10th (County of London) Bn, the London Regiment (joined August 1914, left April 1915)

1/11th (County of London) Bn, the London Regiment (joined August 1914, left April 1915)

1/12th (County of London) Bn, the London Regiment (joined August 1914, left December 1914)

1/16th (County of London) Bn, the London Regiment (joined February 1916)

169th Brigade Machine Gun Company (formed 17 April 1916, moved into 56 MG Bn 1 March 1918)

169th Trench Mortar Battery (joined 17 June 1916)

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Divisional Troops

1/5th Bn, the Cheshires (joined as Pioneers February 1916)

193rd Machine Gun Company (joined 24 December 1916, joined Divisional MG Battalion 1 March1918)

No 56 Machine Gun Battalion (created 1 March1918)

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Divisional Mounted Troops

2nd County of London Yeomanry (left August 1915)

B Squadron, 2nd King Edwards Horse (joined March 1915, left 30 May 1915)

1st London Divisional Cyclist Company (joined April 1916, left May 1916)

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Divisional Artillery

The Divisional Artillery was attached to the 36th (Ulster) Division in September 1915, after which the Brigades were attached to various other Divisions and formations before rejoining in February 1916.

CCLXXX (I City of London) Brigade, RFA

CCLXXXI (II London) Brigade, RFA

CCLXXXII (III London) Brigade, RFA (left January 1917)

CCLXXXIII (IV London) (H) Brigade, RFA (broken up in November 1916)

1st London Heavy Battery, RGA (a Battery of 4 4.7-inch guns which left the Division to join 58th Division in early 1915

56th Divisional Ammunition Column

V.56 Heavy Trench Mortar Battery RFA (formed May 1916, left February 1918)

X.56, Y.56 and Z.56 Medium Mortar Batteries RFA (formed by mid May 1916; in February 1918, Z broken up and batteries reorganised to have 6 x 6-inch weapons each)

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Engineer Units

416th Field Coy (joined May 1916, formerly named 1st (Edinburgh) Field Coy)

512th Field Coy (joined February 1916, formerly named 2/1st (London) Field Coy)

513th Field Coy (joined February 1916, formerly named 2/2nd (London) Field Coy)

1st (London) Field Coy (joined Aug 1914, left Dec 1914)

2nd (London) Field Coy (joined Aug 1914, left Jan 1915)

56th Divisional Signal Company (renamed from 1st London Divisional Signal Company). Original company went with 1st Brigade to Malta and remained there; replaced in February 1916 by the Signals Company from 58th Division.

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Field Ambulances

1st London (joined Aug 14, left June 1916)

2nd London (joined Aug 14, left Dec 1914)

3rd London (joined Aug 14, left Dec 1914)

2/1st London (joined Feb 1916)

2/2nd London (joined Feb 1916)

2/3rd London (joined Feb 1916)

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56th Divisional Train ASC (Originally 170, 171, 172 and 173 Coys but they were detached in November 1915 and moved to Salonika with 28th Division. Replaced by 213, 214, 215 and 216 Coys ASC, from 30th Division.)

247th Divisional Employment Company (joined by 23 June 1917, adopting its number in August)

1st London Mobile Veterinary Section (joined 14 March 1916)

56th Sanitary Section (joined 11 February 1916, left for VII Corps 1 April 1917)

56th Divisional Motor Ambulance Workshop (joined 28 February 1916, left 31 March 1916, absorbed by Divisional Supply Column)