Formed as 39 Brigade-Division RFA in March 1900. It was re-designated as 39 Brigade Royal Field Artillery in 1903. In May 1920 it became 10 Brigade RFA. It changed title again in June 1924 to 10 Field Brigade RA. 10 Field Regiment RA was re-designated from 10 Field Brigade in May 1938. It was on a two battery basis, before changing to a three battery set up in June 1940. Post war 10 Field Regiment RA became 40 Field Regiment in April 1947.
Illustrations of the formation badges under which a unit served or supported are given. This is no guarantee that the unit used this formations badge.
| 3 Sep 39 |  |
2 Infantry Division | Deepcut, Surrey, UK |
| 24 Sep 39 | |
2 Infantry Division | Grez-en-Bouere, France |
| October 39 | |
2 Infantry Division | Landas, France |
| 12 May 40 | |
2 Infantry Division | River Dyle, Belgium |
| 18 May 40 | |
2 Infantry Division | Tournai, Belgium |
| 21 May 40 | |
2 Infantry Division | Laventie, France |
| 23 May | |
2 Infantry Division | Watou, Belgium |
| 29 May | |
2 Infantry Division | Malo les Bains, France |
| Jun 40 |  |
2 Infantry Division | UK |
| Jun 42 | |
2 Infantry Division | India |
| Apr 43 |  |
36 Indian Division | India |
| Sep 43 | |
2 Infantry Division | India |
| Apr 44 | |
2 Infantry Division | Kohima, India |
| Apr 45 | |
2 Infantry Division | Chittagong, Bangladesh |
| Jun 45 | |
2 Infantry Division | Secunderabad, India |
Batteries
| May 20 | 30, 46, 51, 54 |
| May 38 | 30/46, 51/54 |
| Jun 40 | A, B, C |
| Feb 41 | 30, 46, 51/54 |
Equipment
| Sep 39 | 18/25pdr Guns, Morris CDSW Gun Tractors |
| Apr 43 | 30 Battery 6 x 3.7 inch Howitzers – 46 Battery to Light Anti-Aircraft |
| Sep 43 | 30 Battery 3.7 inch Howitzers – remainder 25 pdr |
| Oct 43 | 46 Battery – 105 mm M7 Self Propelled Priest |
| Mar 44 | 24 x 25 pdr |
