51 (London) Heavy Anti-Aircraft Regiment RA(TA) was re-designated 51 (London) Anti-Aircraft Regiment RA(TA) from 51 (London) Anti-Aircraft Brigade RA(TA), in January 1939. It was re-designated as 51 (London) Heavy Anti-Aircraft Regiment RA(TA) in June 1940. The Regiment was re-designated as 71 Heavy Anti-Aircraft Regiment RA, as a War Formed Regiment, in April 1947. The TA unit reconstituted as 451 (London) Heavy Anti-Aircraft Regiment RA(TA) in January 1947. The title was changed to (Chelsea) in 1952, when it was adopted by the Borough.
| Sep 39 | 49 Anti-Aircraft Brigade, 1 Anti-Aircraft Division | London, UK |
| May 40 | 6 Anti-Aircraft Brigade | Harstad, Norway |
| Jun 40 | Re-equipping | Troon Ayrshire, UK |
| Jul 40 | 48 Anti-Aircraft Brigade | London, UK |
| Oct 40 | 4 Anti-Aircraft Brigade – 151 Battery to Crete | Cairo, Egypt |
| Nov 40 | British Troops Egypt | Mersa Matruh, Egypt |
| Mar 41 | 4 Anti-Aircraft Brigade | Tobruk, Libya |
| Sep 41 | 9 Army | Haifa, Palestine |
| Sep 42 | 8 Army – 1 Anti-Aircraft Brigade | Benghazi, Libya |
| May 43 | 12 Anti-Aircraft Brigade | Tunisia |
| Aug 43 | 8 Army – 2 Anti-Aircraft Brigade | Sicily |
| Sep 43 | 2 Anti-Aircraft Brigade | Reggio, Italy |
| Oct 43 | 2 Anti-Aircraft Brigade | Foggia, Italy |
| Nov 43 | 6 Army Group RA | Rivers Sangro & Biferno, Italy |
| Jul 44 | 5 Corps, 2 Anti-Aircraft Brigade | Ancona, Italy |
| Aug 44 | Regiment “Diluted” – a proportion of the men replaced by Basutos |
Anzio, Italy |
| Oct 44 | 2 Anti-Aircraft Brigade | Gothic Line, Italy |
| Apr 45 | 8 Army | Forli, Italy |
Batteries
| Sep 39 | 151, 152, 153 |
| Dec 40 | 16, 151, 152, 153 – 151 Battery detached to Crete |
| Feb 41 | 151 (detached), 152, 153 |
| Apr 41 | 152, 153, 235 (Kent) |
| Jul 41 | 151 Battery captured & disbanded |
| Apr 42 | 152, 153, 242 (Glamorgan) |
