Formed in April 1921 as 99 (Buckinghamshire Yeomanry) Brigade Royal Field Artillery (TF). The brigade was formed by conversion of the Buckinghamshire Yeomanry (Royal Bucks Hussars) (TA). 99 (Buckinghamshire & Berkshire Yeomanry) Field Regiment RA (TA) was re-designated from 99 Field Brigade in November 1938 on a two battery basis. A third battery was raised in July 1940. The 99 (Royal Bucks Yeomanry) Field Regiment RA (TA) title was introduced in May 1942. The Regiment was placed into suspended animation in September 1946 and reconstituted as 299 (Buckinghamshire Yeomanry) Field Regiment RA (TA) in January 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.
(Title changed May 1942 from Buckinghamshire and Berkshire Yeomanry to Royal Bucks Yeomanry)
| 3 Sep 39 |  |
48 Infantry Division | Aylesbury, Buckinghamshire, UK |
| 18 Jan 40 | |
48 Infantry Division | France |
| Feb 40 |  |
2 Infantry Division | France |
| Jun 40 |  |
2 Infantry Division | UK |
| Jun 42 | |
2 Infantry Division | India |
| Nov 42 | 6 Infantry Brigade Group | India | |
| Dec 42 | 6 Infantry Brigade Group | Burma (Myanmar) | |
| Jun 43 | |
2 Infantry Division | India |
| Apr 44 | |
2 Infantry Division | Burma (Myanmar) |
| Jun 45 | |
2 Infantry Division | Secunderabad, India |
Batteries
| Apr 21 | 393, 394 |
| Jun 21 | 393, 394, 395, 396 |
| Nov 38 | 393 (Royal Bucks Yeomanry), 394 (Royal Bucks Yeomanry) – 395 & 396 Batteries to 145 Field Regiment |
| Feb 41 | 393, 394, 472 |
Equipment
| Sep 39 | 12 x 18 pdr Guns, 12 x 4.5 inch Howitzers |
| Dec 42 | 3.7 inch Howitzer & 25 Pdr |
| Oct 43 | 393 Battery 3.7 inch Howitzers, 394 Battery 105mm SP Priest, 472 Battery 25 pdr |
| Mar 44 | 394 Battery 8 x 25 pdr |
| Mar 45 | 24 x 25 pdr |