139 (4th London) Field Regiment RA (TA) was formed in June 1939 with two batteries as a duplicate of 91 Field Regiment. A third battery was raised in January 1941. It was re-designated as 139 Jungle Field Regiment in October 1943 and reverted to the Field role in July 1944. Post war 139 (4th London) Field Regiment RA (TA) went into suspended animation in February 1946 and was disbanded 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.
(Title authorised February 1942)
| Jun 39 |  |
London District | Lewisham, London, UK |
| Sep 39 | |
London District | Mill Hill, London, UK |
| Nov 39 | Home Forces | Tetbury, Gloucestershire, UK | |
| Apr 40 | British Expeditionary Force | Haverskerque, France | |
| May 40 |  |
attached 44 Infantry Division | Oudenaarde, Belgium |
| May 40 | |
attached 44 Infantry Division | Courtrai, Belgium |
| May 40 |  |
3 Corps | Ploegsteert, Belgium |
| May 40 |  |
attached 2 Infantry Division | La Bassée, France |
| May 40 | |
3 Corps | Malo-les-Baines, France |
| Jun 40 |  |
1 Corps | Dunkirk, France |
| Jun 40 | Home Forces | Llanfairfechan, Conwy, UK | |
| Dec 40 |  |
3 Corps | Wrexham, Clwyd, UK |
| Feb 41 | Home Forces | Tenby, Pembrokeshire, UK | |
| Dec 41 | Home Forces | Felixstowe, Suffolk, UK | |
| Jun 42 |  |
War Office Reserve | UK |
| Oct 42 |  |
7 Indian Division | Nowshera, India |
| May 43 | |
7 Indian Division | Ranchi, India |
| Jul 43 | |
7 Indian Division | converted to Jungle Field Regiment |
| Aug 43 | |
7 Indian Division | Arakan, Burma (Myanmar) |
| May 44 | |
7 Indian Division | Kohima, India |
| Jun 44 | |
7 Indian Division | Ranchi, India – reverted to Field Regiment |
| Oct 44 | |
7 Indian Division | Kohima, India |
| Nov 45 | |
7 Indian Division | Rangoon, India |
Batteries
| Jun 39 | 362 (6th London), 364 (8th London) |
| Jan 41 | 362, 364, 503 |
Equipment
| Sep 39 | 4.5 inch Howitzers |
| Dec 39 | 18 pdr Mk II, Morris C8 Quad |
| Nov 41 | 24 x 18/25 pdr Guns |
| Feb 42 | 24, 25 pdr Guns |
| Jul 43 | 16 x 3 inch Mortars & 16 x 3.7 inch Howitzers |
| Oct 44 | 24 x Jungle 25 pdr Guns |