36 (Middlesex) Searchlight Regiment RA (TA) formed in August 1940 by the transfer of 36 (Middlesex) Anti-Aircraft Battalion Royal Engineers (TA) to the RA. The Regiment served in Anti-Aircraft Command in Eastern England, until its conversion to Infantry in 1945. 36 (Middlesex) Searchlight Regiment RA (TA) was converted to 634 Infantry Regiment RA in January 1945. It was re-constituted as 571 (Middlesex) (Mixed) Light Anti-Aircraft/Searchlight 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.
| Aug 40 | Formed from 36 Anti-Aircraft Battalion Royal Engineers | Edgeware, London, UK | |
| Aug 40 |  |
2 Anti-Aircraft Division, 40 Anti-Aircraft Brigade | East Anglia, UK |
| Oct 42 |  |
5 Anti-Aircraft Group, 40 Anti-Aircraft Brigade | East Anglia, UK |
| Sep 43 | |
5 Anti-Aircraft Group, 50 Anti-Aircraft Brigade | UK |
| Jan 44 | |
2 Anti-Aircraft Group, 27 Anti-Aircraft Brigade | UK |
| Jan 45 | Became 634 Infantry Regiment RA |
Batteries
| Sep 39 | 317, 345, 346, 424 |
| Feb 44 | 317, 345, 346 |