The regular army Divisions
Please note that these formations were only nominally of the regular army. From the very beginning some non-regular units were required to make up the full establishment and from as early as 1915 the ranks of regular uunits began to be replenished with "war service only" recruits.

Division	Theatres	Arrival in first theatre
Guards	France & Flanders	Formed in France August 1915
1	France & Flanders	August 1914
2	France & Flanders	August 1914
3	France & Flanders	August 1914
4	France & Flanders	August 1914
5	France & Flanders, Italy	August 1914
6	France & Flanders	August 1914
7	France & Flanders, Italy	October 1914
8	France & Flanders	November 1914
27	France & Flanders, Salonika	December 1914
28	France & Flanders, Salonika	January 1915
29	Gallipoli, Egypt, France & Flanders	April 1915

The first-line Territorial Divisions
Please note that these formations were renamed to have the number designations in 1915. When they first went overseas they were, for example, the East Lancashire Division. Some did not go to a recognised theatre of war and are marked in italic text. The West Lancashire and 1st London Divisions re-formed in France by gathering back together many units that had been sent there independently in 1914 and 1915.

Division	Theatres	Arrival in first theatre
42nd (East Lancashire)	Egypt, Gallipoli, France & Flanders	September 1914
43rd (Wessex)	India	October 1914
44th (Home Counties)	India	October 1914
46th (North Midland)	France & Flanders, Egypt	February 1915
47th (2nd London)	France & Flanders	March 1915
48th (South Midland)	France & Flanders, Italy	March 1915
49th (West Riding)	France & Flanders	April 1915
50th (Northumbrian)	France & Flanders	April 1915
51st (Highland)	France & Flanders	May 1915
52nd (Lowland)	Gallipoli, Palestine, France	July 1915
53rd (Welsh)	Gallipoli, Palestine	July 1915
54th (East Anglian)	Gallipoli, Palestine	August 1915
55th (West Lancashire)	France & Flanders	Re-formed in France, January 1916
56th (1st London)	France & Flanders	Re-formed in France, January 1916
74th (Yeomanry)	Palestine, France & Flanders	Formed in Palestine, March 1917
75th	Palestine	Formed in Egypt, March 1917

The New Army (or Kitchener) Divisions
These formations did not exist before the war.

Division	Theatres	Arrival in first theatre
9th (Scottish)	France & Flanders	May 1915
10th (Irish)	Gallipoli, Salonika, Palestine	August 1915
11th (Northern)	Gallipoli, France & Flanders	August 1915
12th (Eastern)	France & Flanders	May 1915
13th (Western)	Gallipoli, Mesopotamia	June 1915
14th (Light)	France & Flanders	May 1915
15th (Scottish)	France & Flanders	July 1915
16th (Irish)	France & Flanders	December 1915
17th (Northern)	France & Flanders	July 1915
18th (Eastern)	France & Flanders	July 1915
19th (Western)	France & Flanders	July 1915
20th (Light)	France & Flanders	July 1915
21st	France & Flanders	September 1915
22nd	France & Flanders, Salonika	September 1915
23rd	France & Flanders, Italy	August 1915
24th	France & Flanders	September 1915
25th	France & Flanders	September 1915
26th	France & Flanders, Salonika	September 1915
30th	France & Flanders	November 1915
31st	Egypt, France & Flanders	December 1915
32nd	France & Flanders	November 1915
33rd	France & Flanders	November 1915
34th	France & Flanders	January 1916
35th	France & Flanders	January 1916
36th (Ulster)	France & Flanders	October 1915
37th	France & Flanders	August 1915
38th (Welsh)	France & Flanders	November 1915
39th	France & Flanders	March 1916
40th	France & Flanders	June 1916
41st	France & Flanders, Italy	May 1916

The second-line Territorial Divisions
Please note that these formations were only released to go to a theatre of war by the Military Service Act of 1916. Some did not go to a recognised theatre of war and are marked in italic text. Those that are 'missing' from the list remained at home and can be seen on the page covering home-based Divisions.

Division	Theatres	Arrival in first theatre
45th (2nd Wessex)	India	December 1914
57th (2nd West Lancashire)	France & Flanders	February 1917
58th (2/1st London)	France & Flanders	January 1917
59th (2nd North Midland)	Ireland, France & Flanders	February 1917 (France)
60th (2/2nd London)	France, Salonika, Palestine	June 1916
61st (2nd South Midland)	France & Flanders	May 1916
62nd (2nd West Riding)	France & Flanders	April 1915
66th (2nd East Lancashire)	France & Flanders	March 1917

Other Divisions.

Division	Theatres	Arrival in first theatre
63rd (Royal Naval)	Belgium, Gallipoli, France & Flanders	October 1914 (Belgium)