In late 1916, an Army command sanctioned the formation of three new Divisions for home service. 73rd Division was formed in November 1916, initially of a mixture of Provisional (training) Battalions and similar units of the other arms with a few units that had been detached from active service overseas.

The Division was part of Southern Army, Home Forces; it provided garrisons for various places in the United Kingdom, but was principally a place for training and recuperation of men recovering from wounds or sickness or a more permanent place for men of lower medical categories.

On 21 December 1917, orders were given to break up the Division, and the final units were transferred elsewhere on 8 April 1918.

218th Brigade

12th Bn, the King's Own (joined as 41st Provisional Bn November 1916, disbanded July 1918)

26th Bn, the King's (Liverpool) (joined as 42nd Provisional Bn November 1916, disbanded 1919)

14th Bn, the Loyal North Lancs (joined as 44th Provisional Bn November 1916, disbanded by 17 December 1917)

267th Bn (a Graduated Battalion of the Training Reserve, joined 23 July 1917, disbanded 5 November 1917. Redesignated 52nd Leicesters 27 October 1917.)

219th Brigade

8th Bn, the Dorsets (joined 7 November 1916, disbanded 3 December 1917)

13th Bn, the Loyal North Lancs (joined by 4 December 1916, disbanded August 1918)

28th Bn, the Manchesters (joined as 45th Provisional Bn November 1916, disbanded November 1918)

270th Bn (a Graduated Battalion of the Training Reserve, joined 9 July 1917, left January 1918. Redesignated 52nd KOYLI 27 October 1917.)

220th Brigade

2/4th Bn, the Yorkshire Regiment (joined 9 November 1916, disbanded by 21 December 1917)

2/5th Bn, the Yorkshire Regiment (joined 9 November 1916, disbanded March 1918)

17th Bn, the Yorkshire Regiment (joined 4 December 1916, disbanded 5 November 1917)

273rd Bn (a Graduated Battalion of the Training Reserve, joined 23 July 1917, left 15 January 1918. Redesignated 52nd Durham LI 27 October 1917.)

274th Bn (a Graduated Battalion of the Training Reserve, joined 23 July 1917, left 11 March 1918. Redesignated 52nd Royal Warwicks 27 October 1917.)

Divisional Mounted Troops

73rd Divisional Cyclist Company (joined 18 December 1916, broken up 1 April 1918. Redesignated 73rd Coy, Army Cyclist Corps September 1917).

Divisional Artillery

All units were broken up 25 February 1918

CCCLIV Brigade, RFA

CCCLV Brigade, RFA

73rd Divisional Ammunition Column RFA (joined 20th November 1916, formerly 9th Provisional BAC)

Engineer Units

546th Field Company RE (joined 20th November 1916, formerly 1/6th Kent Fortress Company; left June 1918)

547th Field Company RE (joined 20th November 1916, formerly 1/7th Kent Fortress Company; left June 1918)

648th Field Company RE (joined 20th November 1916, formerly 9th Provisional Field Company; left June 1918)

73rd Divisional Signal Company (joined 20th November 1916, formerly 9th Provisional Brigade Signal Company; disbanded March 1918)

Field Ambulances

All units joined 28 November 1917

307th (Home Counties) Field Ambulance RAMC

308th (Home Counties) Field Ambulance RAMC

309th (Home Counties) Field Ambulance RAMC

Other units

73rd Divisional Train ASC

58th Mobile Veterinary Section (joined 24 January 1917)

106th Sanitary Section RAMC