157 Field Regiment RA was formed in India in December 1940 with two batteries. A third battery was formed in January 1941. In May 1942 the Regiment was reduced to 2 batteries when 515 Battery joined 164 Field Regiment. Due to heavy casualties in Libya, 157 Field Regiment RA was disbanded in August 1942. RHQ was disbanded in the Middle East and 421 Battery was disbanded in India. 64 Battery was placed in suspended animation. It was re-formed in 165 Field Regiment four months later.
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.
| Dec 40 | Formed | India | |
| Dec 40 |  |
Central Command | India |
| May 41 |  |
10 Indian Division | Iraq |
| Jun 41 | |
10 Indian Division | Persia (Iran) |
| Aug 41 | |
10 Indian Division | Iraq |
| May 42 | |
10 Indian Division | N Africa |
| Jun 42 | |
10 Indian Division | N Africa |
| Jun 42 |  |
GHQ Middle East Forces | The Cauldron, Libya |
| Aug 42 | Disbanded |
Batteries
| Dec 40 | 64, 421 |
| Jan 41 | 64, 421, 515 |
| May 42 | 64, 421 |
Equipment
| Jun 42 | 25 pdr |