120 Heavy Anti-Aircraft Regiment RA(TA) was formed at Lawrenny Castle in January 1941. The Regiment was disbanded in June 1944.
| Jan 41 | Formed | Lawrenny Castle, Pembrokeshire, UK |
| Jan 41 | 61 Anti-Aircraft Brigade, 9 Anti-Aircraft Division | Pembroke, Pembrokeshire, UK |
| Aug 41 | 26 Anti-Aircraft Brigade, 1 Anti-Aircraft Division | London, UK |
| Jan 43 | War Office Reserve | UK |
| May 43 | Middle East Forces | Port Tewfik, Egypt |
| Jun 43 | 20 Anti-Aircraft Brigade, 9 Army | Cyprus |
| Oct 43 | Regiment “Diluted” by Basuto troops of the African Pioneer Corps |
Cyprus |
| Jun 44 | Disbanded |
Batteries
| Jan 41 | 381, 384, 386 |
| Aug 41 | 248, 381, 384, 386 |
| Oct 42 | 248, 381, 384 |
Gun Sites Occupied
384 Battery
| Dates | Gun Site | Under Command | Gun Defended Area |
| Mar 41 | O1 Royal Ordnance Factory Pembrey P9 West Pennar |
79 HAA Rgt | Milford Haven |
| Mar 41 | O2 Llanelli N12 Temporary site |
79 HAA Rgt | Swansea |
| 5 Apr 41 | N12 Temporary site N9 Bryn |
79 HAA Rgt | Swansea |
| May-Aug 41 | N7 Briton Ferry N9 Bryn |
79 HAA Rgt | Swansea |
386 Battery
| Dates | Gun Site | Gun Defended Area |
| May-Aug 41 | N3A Jersey Marine (2 sections) | Swansea |
