In May 1938 1 Brigade RHA was re-organised as 1 Regiment Royal Horse Artillery with two batteries. It became a three battery unit in December 1940. 1 Royal Horse Artillery assumed the role of a field regiment in 1 Armoured Division in January 1946.
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 |  |
1 Support Group | Bulford, Wiltshire, UK 1 detachment each from A/E and B/O Batteries attached 8 Infantry Division, Palestine |
| Sep 39 | |
1 Support Group | Blandford, Dorset, UK |
| 21 Oct 39 | British Expeditionary Force | France | |
| Jun 40 | Home Forces | UK | |
| Oct 40 |  |
British Troops Egypt | N Africa |
| Feb 41 | 3 Armoured Brigade Group | N Africa | |
| Apr 41 |  |
Middle East Forces | N Africa |
| Jul 41 | Tobruk Garrison | RSM Clarke gathered various captured Italian howitzers and improvised sights for them. “Mr Clarke’s Guns” played an important part in the defence of the fortress. |
|
| Dec 41 |  |
8 Army | N Africa |
| Feb 42 |  |
4 Armoured Brigade Group | N Africa |
| Aug 42 |  |
22 Armoured Brigade Group | N Africa |
| Sep 42 |  |
10 Armoured Division | N Africa |
| Oct 42 | |
10 Armoured Division | Alamein, Egypt |
| Jan 43 | |
10 Armoured Division | Syria |
| May 43 |  |
9 Armoured Brigade Group | Syria |
| Jun 43 | |
9 Armoured Brigade Group | Palestine |
| Nov 43 | |
9 Armoured Brigade Group | Syria |
| Mar 44 | |
9 Armoured Brigade Group | N Africa |
| May 44 | |
9 Armoured Brigade Group | Italy |
| Sep 44 | |
8 Army | Italy |
| Nov 44 | |
9 Armoured Brigade Group | Italy |
| Jun 45 |  |
Allied Forces HQ | Italy |
Batteries
| 3 Sep 39 | A/E, B/O |
| Feb 42 | A, B, E |
| Jun 42 | A, B, E, ZZ Anti-Tank |
| Sep 42 | A, B, E |
Equipment
| Sep 39 | 18/25 pdr, Light Dragons & Light Tank Mk VIB Observation Post |
| Dec 40 | 25 pdr |
| Sep 42 | Stuart Observation Post Tanks |
| Dec 44 | 25 pdr Self Propelled Sexton |