90 Light Anti-Aircraft Regiment RA was formed in November 1941 by conversion of 7th Battalion The South Wales Borderers, with three batteries. The Regiment was disbanded in January 1945 .
| Nov 41 | Formed from 7th Battalion South Wales Borderers | |
| Nov 41 | Home Forces | UK |
| Jan 42 | 1 Infantry Division | UK |
| Mar 43 | 1 Infantry Division | N Africa |
| Jun 43 | 1 Infantry Division | Pantelleria |
| Jun 43 | 1 Infantry Division | N Africa |
| Dec 43 | 1 Infantry Division | Italy |
| Nov 44 | Allied Forces HQ | Italy |
| Jan 45 | Disbanded |
Batteries
| Nov 41 | 311, 312, 313 |
