6 Anti-Aircraft Z Regiment RA was formed in September 1940 with two batteries (this was eventually doubled to four) in 1 Anti-Aircraft Division. 171 Battery occupied sites in Colchester for the whole of 1942. 6 Anti-Aircraft Z Regiment RA disbanded in March 1945.
| Sep 40 | Formed | ||
| Sep 40 |  |
1 Anti-Aircraft Division, 26 Anti-Aircraft Brigade | London, UK |
| Oct 42 |  |
1 Anti-Aircraft Group , 49 Anti-Aircraft Brigade | London, UK |
| Aug 43 | |
1 Anti-Aircraft Group, 37 Anti-Aircraft Brigade Designated “Mixed” |
London, UK |
| Apr 44 | Became 6 Anti-Aircraft Area Mixed Regiment | ||
| Aug 44 | |
1 Anti-Aircraft Group, 26 Anti-Aircraft Brigade | London, UK |
| Mar 45 | Disbanded |
Batteries
| Sep 40 | 112, 126 |
| Jan 41 | 112, 126, 127 |
| Aug 41 | 128, 148, 171, 173 |
| Oct 42 | 128, 148, 190, 197 |
Batteries manned by Home Guard
| Battery | Home Guard Unit | Date from |
| 128 Battery | 101 City of London (Mixed) | Nov 42 |
| 148 Battery | 102 City of London (Mixed) | Nov 42 |
| 190 Battery | 103 City of London (Mixed) | Nov 42 |
| 197 Battery | 102 Kent (Mixed) | Jul 42 |
Gun Sites Occupied
171 Z Battery
Became independent Oct 42
| Dates | Gun Site | Gun Defended Area |
| Jan-Dec 42 | C10 Lexden – Z Projectors | Colchester |
| Dec 42 | Abbey Field – Z Projectors with 196 Z Battery | Colchester |