Authorised in December 1914, this Division was originally part of the Fifth New Army, and was numbered 40th. However, the Fourth New Army was broken up in April 1915, and the Division was renumbered 33rd, part of K4. It was formed of many units that had been raised by public subscription and private projects. The Division began to assemble at Clipstone Camp in Nottinghamshire on 1 July 1915, and moved to the Bulford area on 3 August 1915. It moved to France in November 1915 (less the artillery which joined it there later, and the Divisional train) and served with distinction on the Western Front throughout the war.

The Battle of Albert (first phase of the Battle of the Somme 1916)

The Battle of Bazentin (second phase of the Battle of the Somme 1916), and the Attacks on High Wood

The First Battle of the Scarpe (opening phase of the Arras Offensive) 19th Brigade only

The Second Battle of the Scarpe (second phase of the Arras Offensive)

Flanking Operations Round Bullecourt

The Battle of the Menin Road (third phase of the Third Battle of Ypres)

The Battle of the Polygon Wood (fourth phase of the Third Battle of Ypres)

The Battle of Messines, 1918 (second phase of the Battles of the Lys) (100th Brigade)

The Battle of Hazebrouck (third phase of the Battles of the Lys)

The Battle of Bailleul (fourth phase of the Battles of the Lys) (110th Brigade)

In the above action, the Division played a part in the Defence of Neuve Eglise

The First Battle of Kemmel (fifth phase of the Battles of the Lys)

In the above action, the Division played a part in the recapture of Ridge Wood

The Battle of the St Quentin Canal (fourth 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 Selle

In the above action, the Division was relieved on 26 October after capturing Englefontaine, on the southern edge of the Forest of Mormal. Back in action on 5 November it advanced through the forest and crossed the Sambre. It wa snear Leval in the Sambre valley on 11 November 1918.

The Division proveeded to concetrate around Berlaimont, and on 15 November moved to Montingny near Le Cateau, then on 6 December to Hornoy, west of Amiens. Here it demobilised. The Division ceased to exist on 30 June 1918.

It had suffered casualties of 37,404 killed, wounded and missing.

98th Brigade

18th (Service) Bn, the Royal Fusiliers (joined June 1915, transferred to 19th Brigade 27 November 1915)

19th (Service) Bn, the Royal Fusiliers (joined June 1915, left 28 February 1916)

20th (Service) Bn, the Royal Fusiliers (joined June 1915, transferred to 19th Brigade 27 November 1915)

21st (Service) Bn, the Royal Fusiliers (joined June 1915, left 28 February 1916)

4th (Extra Reserve) Bn, the King's (Liverpool) (joined 27 February 1916)

1/4th Bn, the Suffolks (joined 28 February 1916, left February 1918)

1st Bn, the Middlesex (joined 27 November 1915 from 19th Brigade)

2nd Bn, the Argyll & Sutherland Highlanders (joined 27 November 1915 from 19th Brigade)

98th Brigade Machine Gun Company (joined 28 April 1916, moved into 33 MG Bn by 19 February 1918)

98th Trench Mortar Battery (formed by 30 June 1916)

99th Brigade

The Brigade was transferred as a whole to the 2nd Division on 25 November 1915

17th (Service) Bn, the Royal Fusiliers (joined June 1915)

22nd (Service) Bn, the Royal Fusiliers (joined June 1915)

23rd (Service) Bn, the Royal Fusiliers (joined June 1915)

24th (Service) Bn, the Royal Fusiliers (joined June 1915)

100th Brigade

13th (Service) Bn (West Ham), the Essex (joined August 1915, left 22 December 1915)

16th (Service) Bn (Public Schools), the Middlesex (joined July 1915, left 25 February 1916)

17th (Service) Bn (1st Football), the Middlesex (joined July 1915, left 8 December 1915)

16th (Service) Bn (Church Lads Brigade), the King's Royal Rifle Corps (joined June 1915)

1st Bn, the Queen's (joined 15 December 1915, left 14 February 1918)

2nd Bn, the Worcesters (joined 20 December 1915)

1/9th Bn (Glasgow Highlanders), the Highland Light Infantry (joined 29 May 1916)

1/6th Bn, the Cameronians (Scottish Rifles) (joined and left February 1916)

100th Brigade Machine Gun Company (joined 28 April 1916, moved into 33 MG Bn by 19 February 1918)

100th Trench Mortar Battery (formed by 13 June 1916)

19th Brigade

This Brigade joined the Division from the 2nd Division on 25 November 1915

18th (Service) Bn, the Royal Fusiliers (joined from 98th Brigade 27 November 1915, left 26 February 1916)

20th (Service) Bn, the Royal Fusiliers (joined from 98th Brigade 27 November 1915, disbanded February 1918)

2nd Bn, the Royal Welsh Fusiliers (joined with the Brigade, left 4 February 1918)

1st Bn, the Cameronians (Scottish Rifles) (joined with the Brigade)

1/5th Bn, the Cameronians (Scottish Rifles) (joined wth the Brigade, became 5th/6th Bn May 1916)

1st Bn, the Queen's (joined from 1ooth Brigade 5 February 1918)

19th Brigade Machine Gun Company (formed 24 February 1916, moved into 33 MG Bn by 19 February 1918)

19th Trench Mortar Battery (formed by 24 June 1916)

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Divisional Mounted Troops

F Squadron, the North Irish Horse (joined January 1915, redesignated at B Sqn on 25 May 1916, left 19 April 1916 for 1st Cavalry Division)

33rd Divisional Cyclist Company (formed by 26 July 1915, left 19 April 1916 for 1st Cavalry Division)

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Divisional Artillery

The original Divisional artillery was designated "Camberwell", as it was raised there by the Mayor and a committee between January and June 1915. Initial assembly and training took place in Dulwich. It joined the Division at Bulford between 5 and 8 August 1915. However the artillery did not proceed to France with Division. Instead, it took the artillery of the 54th (East Anglian) Division. 33rd Divisional artillery crossed to France and rejoined its Division in December 1915.

CLVI Brigade RFA

CLXII Brigade RFA

CLXVI Brigade RFA (broken up 12 September 1916)

CLXVII (H) Brigade RFA (broken up 12 September 1916)

126 (Camberwell) Heavy Battery RGA (left for XXII Heavy Artillery Group on 2 May 1916)

33rd Divisional Ammunition Column

V.33 Heavy Trench Mortar Battery RFA (formed by 29 May 1916, broken up in February 1918)

X.33, Y.33 and Z.33 Medium Mortar Batteries RFA (formed by 4 May 1916; Z Bty broken up in February 1918)

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Engineer Units

212th Field Company RE (Tottenham) (joined at Clipstone Camp on 14 July 1915)

222nd Field Company RE (Tottenham) (joined at Clipstone Camp on 14 July 1915)

226th Field Company RE (Tottenham) (joined at Bulford on 31 July 1915, left for 2nd Division 2 December 1915)

11th Field Company RE (joined from 2nd Division 2 December 1915)

33rd Signal Company RE (Tottenham) (joined at Bulford on 31 July 1915)

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Field Ambulances

19th Field Ambulance (joined from 2nd Division Nov 1915)

99th Field Ambulance (joined by May 1915)

100th Field Ambulance (joined by May 1915 and left for 2nd Division Nov 15)

101st Field Ambulance (joined by May 1915)

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Divisional Troops

18th (Service) Bn (1st Public Works Pioneers), the Middlesex (joined at Clipstone Camp on 13 July 1915)

F Squadron , the North Irish Horse (joined January 1915, left April 1916)

248th Machine Gun Company MGC (joined 21 July 1917, merged into MGC Battalion by 19 February 1918)

33rd Machine Gun Battalion MGC (formed 9-19 February 1918)

19th Motor Machine Gun battery (joined 9 November 1915, but left and moved to France by 6 February 1916)

33rd Divisional Train ASC (225,226, 227 and 228 Companies. Embarked for France 12 November 1915, but transferred in March 1916 to 29th Division. 170, 171, 172 and 173 Companies, formerly the 28th Divisional Train, joined on 13 November 1915. 172 Company switched with 8 Company from 2nd Divisional Train in late November 1915)

43rd Mobile Veterinary Section AVC (joined 16 September 1915)

230th Divisional Employment Company (joined by 1 June 1917)

73rd Sanitary Section (left for XV Corps 31 March 1917)

33rd Divisional Motor Ambulance Workshop (absorbed by Divisional Supply Column on 31 March 1916)