53 (City of London) Heavy Anti-Aircraft Regiment RA (TA) was re-designated as 53 (City of London) Anti-Aircraft Regiment RA (TA) from 53 Anti-Aircraft Brigade RA(TA) in January 1939. It was re-designated as Heavy Anti-Aircraft in June 1940. It served in France in 1939. On return to the UK it was in Anti-Aircraft Command until moving to India in May 1942. 53 (City of London) Heavy Anti-Aircraft Regiment RA (TA) was converted to 85 Medium Regiment RA (TA) in August 1944. It was placed in suspended animation in March 1946 and reconstituted as 453 (City of London) Heavy Anti-Aircraft 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.
| Sep 39 |  |
5 Anti-Aircraft Division | Bramley, Surrey, UK |
| Oct 39 | 12 Anti-Aircraft Brigade, Advanced Air Striking Force | Reims, France | |
| May 40 | 12 Anti-Aircraft Brigade, Advanced Air Striking Force | Troyes, France | |
| Jun 40 | Haddock Force | Marseille, France | |
| Jun 40 | 158 Battery evacuated with 12 Anti-Aircraft Brigade | St Nazaire, France | |
| Jun 40 | Remainder evacuated to Gibraltar | Marseille, France | |
| Jul 40 |  |
1 Anti-Aircraft Division, 49 Anti-Aircraft Brigade | London, UK |
| Oct 40 |  |
6 Anti-Aircraft Division, 28 Anti-Aircraft Brigade | Rainham, Kent, UK |
| Feb 41 | |
1 Anti-Aircraft Division, 48 Anti-Aircraft Brigade | Croydon, London, UK |
| Oct 41 | Home Forces | Dover, Kent, UK | |
| May 42 |  |
Eastern Command, 1 Indian Anti-Aircraft Brigade | Calcutta, India |
| Mar 43 | |
Eastern Command, 2 Indian Anti-Aircraft Brigade | Calcutta, India |
| May 44 | |
Eastern Command, 9 Anti-Aircraft Brigade | Nira, India |
| Aug 44 | Became 85 Medium Regiment |
Batteries
| Sep 39 | 157, 158 (City of London), 159 (Lloyds) |
| Jul 43 | 154 (London), 157, 158, 202 |
| Aug 44 | On conversion 154 Battery to 87 Medium Regiment |
Gun Sites Occupied
157 Battery
| Dates | Gun Sites | Comments | Gun Defended Area |
| Dec 41 | ZS4 Bostall Heath | Personnel only | London IAZ |
| Dec 41 | ZS7 Eltham | Personnel only | London IAZ |
| Dec 41 | ZS21 Crayford | Personnel only | London IAZ |
159 Battery
| Dates | Gun Sites | Comments | Gun Defended Area |
| Dec 41 | ZS15 Norbury | Personnel only | London IAZ |
| Dec 41 | ZS23A Summerhouse | Personnel only | London IAZ |
| Dec 41 | ZS9 Sundridge Park | Personnel only | London IAZ |