The Division was formed during 1939 to take responsibility for the air defence of the Thames Estuary, Essex and North Kent. The existing 27 (Home Counties), 28 (Thames & Medway), 29 (East Anglian) and 37 Anti-Aircraft Brigades were transferred to this new formation, together with new formations and units of the Royal Artillery and Royal Engineers.
On re-organisation of Anti-Aircraft Command in October 1942, most of 6 Anti-Aircraft Division became 2 Anti-Aircraft Group.
HQ Uxbridge, London
Order of Battle 1939
| 27 (Home Counties) Anti-Aircraft Brigade – at Lingfield, Surrey |
| 31 (City of London Rifles) Anti-Aircraft Battalion, Royal Engineers – searchlight unit converted from infantry in 1935 |
| 34 (The Queen’s Own Royal West Kent) Anti-Aircraft Battalion Royal Engineers – searchlight unit converted from infantry in 1935 |
| 70 (Sussex) Searchlight Regiment – new unit raised in 1938 |
| 28 (Thames & Medway) Anti-Aircraft Brigade – at Chatham, Kent |
| 55 (Kent) Anti-Aircraft Regiment – formed in 1925 |
| 58 (Kent) Anti-Aircraft Regiment – unit converted from medium artillery in 1935 |
| 75 (Home Counties) (Cinque Ports) Anti-Aircraft Regiment – unit converted from field artillery in 1938 |
| 89 (Cinque Ports) Anti-Aircraft Regiment – new unit raised as duplicate of 75 Anti-Aircraft Regiment in 1939 |
| 29 (East Anglian) Anti-Aircraft Brigade – at South Kensington, London – came under operational command 7 September 1939 |
| 28 (Essex) Anti-Aircraft Battalion, Royal Engineers – searchlight unit formed in 1935 |
| 29 (Kent) Anti-Aircraft Battalion, Royal Engineers – searchlight unit formed in 1935 |
| 73 (Kent Fortress) Anti-Aircraft Battalion, Royal Engineers – searchlight unit partly converted from fortress engineers in 1939 |
| 74 (Essex Fortress) Anti-Aircraft Battalion, Royal Engineers – searchlight unit partly converted from fortress engineers in 1939 |
| 37 Anti-Aircraft Brigade – at Edmonton, London |
| 59 (The Essex Regiment) Anti-Aircraft Regiment – unit converted from infantry in 1935 |
| 61 (Middlesex) Anti-Aircraft Regiment – unit converted from infantry in 1935 |
| 79 (Hertfordshire Yeomanry) Anti-Aircraft Regiment – unit converted from field artillery in 1938 |
| 82 (Essex) Anti-Aircraft Regiment – new unit raised in 1937 |
| 90th Anti-Aircraft Regiment – new unit raised in 1939 |
| 56 Light Anti-Aircraft Brigade – at Uxbridge |
| 11 (City of London Yeomanry) Light Anti-Aircraft Regiment – unit converted from horse artillery in 1939 |
| 12 (Finsbury Rifles) Light Anti-Aircraft Regiment – unit converted from Heavy Anti-Aircraft in 1939 |
| 16 Light Anti-Aircraft Regiment – new unit raised in 1938 |
| 17 Light Anti-Aircraft Regiment – new unit raised in 1938 |
HQ Chelmsford, Essex
Order of Battle 1940-41
| 6 Anti-Aircraft Brigade – covering Essex airfields |
| 12 (Finsbury Rifles) Light Anti-Aircraft Regiment |
| 49 Light Anti-Aircraft Regiment – new unit formed 1940 |
| 32 (7th City of London) Searchlight Regiment – converted from infantry in 1935 |
| 33 (St Pancras) Searchlight Regiment – converted from infantry in 1935 |
| 28 Light Anti-Aircraft Brigade – covering South Thames, Chatham and Dover |
| 55 Heavy Anti-Aircraft Regiment |
| 58 Heavy Anti-Aircraft Regiment |
| 90 Heavy Anti-Aircraft Regiment |
| 29 Anti-Aircraft Brigade – covering Essex airfields and Harwich |
| 48 Light Anti-Aircraft Regiment – new unit formed 1940 |
| 28 (Essex) Searchlight Regiment |
| 74 (Essex Fortress) Searchlight Regiment |
| 37 Anti-Aircraft Brigade – covering North Thames |
| 59 (The Essex Regiment) Heavy Anti-Aircraft Regiment |
| 61 (Middlesex) Heavy Anti-Aircraft Regiment |
| Part of 75 (Home Counties) (Cinque Ports) Heavy Anti-Aircraft Regiment |
| 17 Light Anti-Aircraft Regiment |
| 2 Light Anti-Aircraft Regiment, Royal Canadian Artillery – from 1 Canadian Division |
| 56 Anti-Aircraft Brigade – covering Kent airfields |
| 16 Light Anti-Aircraft Regiment |
| 29 (Kent) Searchlight Regiment |
| 73 (Kent Fortress) Searchlight Regiment |
| Divisional unit |
| 6 Anti-Aircraft Z Regiment – formed in September 1940 |
Order of Battle 1941-42
| 6 Anti-Aircraft Brigade |
| 121 Heavy Anti-Aircraft Regiment – from 29 Anti-Aircraft Brigade Feb 42 |
| 34 Light Anti-Aircraft Regiment – joined Apr 42; to 50 (Northumbrian) Infantry Division May 42 |
| 49 Light Anti-Aircraft Regiment – to 28 Anti-Aircraft Brigade Jun 42 |
| 131 Light Anti-Aircraft Regiment – converted from 81 Searchlight Regiment in 29 Anti-Aircraft Brigade; joined Apr 42 but rostered for overseas service and became unbrigaded soon afterwards |
| 32 Searchlight Regiment – to 56 Anti-Aircraft Brigade Aug 42 |
| 33 Searchlight Regiment |
| 28 Anti-Aircraft Brigade |
| 55 Heavy Anti-Aircraft Regiment – left Spring 42 to War Office control, then to Persia and Iraq Command |
| 58 Heavy Anti-Aircraft Regiment – to 9 Anti-Aircraft Division Autumn 41 |
| 59 Heavy Anti-Aircraft Regiment – from 37 Anti-Aircraft Brigade Autumn 41, to 8 Anti-Aircraft Division Dec 41 |
| 72 (Hampshire) Heavy Anti-Aircraft Regiment – joined Jan 42; to War Office control by May 42, then to 71 Anti-Aircraft Brigade |
| 76 Heavy Anti-Aircraft Regiment – joined Jun, left Jul 42, later in Operation Torch |
| 85 (Tees) Heavy Anti-Aircraft Regiment – joined Autumn 41; left Jun 42, later Operation Torch |
| 90 Heavy Anti-Aircraft Regiment – unbrigaded Jul 42, then to 71 Anti-Aircraft Brigade Sep 42 |
| 127 Heavy Anti-Aircraft Regiment – new unit formed Aug 41, joined Autumn 41, to 71 Anti-Aircraft Brigade Jun 42 |
| 4 (Ulster) Light Anti-Aircraft Regiment – converted from 3 (Ulster) Searchlight Regiment Feb 42; to 56 Anti-Aircraft Brigade by May 42 |
| 16 Light Anti-Aircraft Regiment– left Jul 41, later to Middle East Forces |
| 43 Light Anti-Aircraft Regiment – joined Jul 41, left Dec 41; later to Ceylon |
| 49 Light Anti-Aircraft Regiment – from 6 Anti-Aircraft Brigade Jun 42 |
| 69 Light Anti-Aircraft Regiment – new unit formed Dec 40; to 56 Anti-Aircraft Brigade Jan 42 |
| 132 Light Anti-Aircraft Regiment – from 71 Anti-Aircraft Brigade Jul 42 |
| 12 Anti-Aircraft Z Regiment – from 56 Anti-Aircraft Brigade Jan 42 |
| 29 Anti-Aircraft Brigade – Disbanded 14 February 1942 |
| 71 (Forth) Heavy Anti-Aircraft Regiment – from 11 Anti-Aircraft Division Jan 42, then to War Office control, later in Operation Torch |
| 99 (London Welsh) Heavy Anti-Aircraft Regiment – to Orkney & Shetland Defences (OSDEF) May 41 |
| 121 Heavy Anti-Aircraft Regiment – from 37 Anti-Aircraft Brigade May 41; to 6 Anti-Aircraft Brigade Feb 42 |
| 48 Light Anti-Aircraft Regiment – left UK Dec 41, captured in Java Mar 42 |
| 81 Light Anti-Aircraft Regiment – new unit formed Aug 41, joined Autumn 41; to 5 Anti-Aircraft Division by May 42 |
| 28 Searchlight Regiment – to 37 Anti-Aircraft Brigade Spring 42 |
| 74 Searchlight Regiment – to 8 Anti-Aircraft Division Jan 42 |
| 81 Searchlight Regiment – joined Jan 42; converted to 131 Light Anti-Aircraft Regiment in 6 Anti-Aircraft Brigade |
| 37 Anti-Aircraft Brigade |
| 59 Heavy Anti-Aircraft Regiment – to 28 Anti-Aircraft Brigade Summer 41 |
| 61 Heavy Anti-Aircraft Regiment – left Summer 41; later to Middle East Forces |
| 75 Heavy Anti-Aircraft Regiment – from 28 Anti-Aircraft Brigade Summer 41; to War Office control Apr 42, later to Persia and Iraq Command |
| 121 Heavy Anti-Aircraft Regiment – new unit formed Jan 41; to 29 Anti-Aircraft Brigade May 41 |
| 17 Light Anti-Aircraft Regiment – from 56 Anti-Aircraft Brigade; to 12 Anti-Aircraft Division Autumn 41 |
By December 1941, the 37 Anti-Aircraft Brigade only had the 75 Heavy Anti-Aircraft Regiment under its command; it was then joined by:
| 66 Heavy Anti-Aircraft Regiment – joined Aug 42 |
| 71 Heavy Anti-Aircraft Regiment – from 29 Anti-Aircraft Brigade May 42; left Jul 42, later Operation Torch |
| 84 Heavy Anti-Aircraft Regiment – joined Spring 42; to 56 Anti-Aircraft Brigade Aug 42 |
| 102 Heavy Anti-Aircraft Regiment– joined Aug 42 |
| 104 Heavy Anti-Aircraft Regiment – joined Apr 42 |
| 131 Heavy Anti-Aircraft Regiment – joined Jul 42, to 4 Anti-Aircraft Division Aug 42 |
| 167 (Mixed) Heavy Anti-Aircraft Regiment – new unit formed Aug, joined Sep 42 |
| 4 Light Anti-Aircraft Regiment – from 28 Anti-Aircraft Brigade, then unbrigaded Jul 42 |
| 31 Light Anti-Aircraft Regiment – joined Jun 42; unbrigaded Aug 42 |
| 86 Light Anti-Aircraft Regiment – joined from 56 Anti-Aircraft Brigade Apr 42 |
| 140 Light Anti-Aircraft Regiment – new unit formed Jul, joined Aug 42 |
| 28 Searchlight Regiment – from 29 Anti-Aircraft Brigade Spring 42, to 56 Anti-Aircraft Brigade Jun 42 |
| 56 Anti-Aircraft Brigade |
| 4 Light Anti-Aircraft Regiment – from 37 Anti-Aircraft Brigade Spring 42 |
| 50 Light Anti-Aircraft Regiment – from 7 Anti-Aircraft Division Mar 42 |
| 69 Light Anti-Aircraft Regiment – from 28 Anti-Aircraft Brigade Jan 42; to India Feb 42 |
| 86 Light Anti-Aircraft Regiment – from 1 Anti-Aircraft Division Jan 42, to 37 Anti-Aircraft Brigade Apr 42 |
| 29 Searchlight Regiment – to 8 Anti-Aircraft Division Jan 42 |
| 73 Searchlight Regiment |
| 6 Anti-Aircraft Z Regiment – to 1 Anti-Aircraft Division Summer 41 |
| 12 Anti-Aircraft Z Regiment – new unit formed Mar 41; to 28 Anti-Aircraft Brigade Jan 42 |
By May 1942, 56 Anti-Aircraft Brigade only had the 4 Light Anti-Aircraft Regiment and 73 Searchlight Regiment under its command; it was then joined by:
| 84 Heavy Anti-Aircraft Regiment – from 37 Anti-Aircraft Brigade Aug 42, left Sep 42, later in Operation Torch |
| 101 Heavy Anti-Aircraft Regiment – joined Jun 42, left Jul 42, later to India |
| 66 Light Anti-Aircraft Regiment – joined Jun 42, to 71 Anti-Aircraft Brigade same month |
| 28 Searchlight Regiment – from 37 Anti-Aircraft Brigade Jun 42 |
| 32 Searchlight Regiment – from 6 Anti-Aircraft Brigade Aug 42 |
| 71 Anti-Aircraft Brigade – joined June 1942 |
| 72 Heavy Anti-Aircraft Regiment – from War Office control (previously 28 Anti-Aircraft Brigade) Jun 42, left Jul 42; later to Operation Torch |
| 85 Heavy Anti-Aircraft Regiment – from 28 Anti-Aircraft Brigade Jul 42; later in Operation Torch |
| 90 Heavy Anti-Aircraft Regiment – from unbrigaded (previously 28 Anti-Aircraft Brigade) Sep 42 |
| 127 Heavy Anti-Aircraft Regiment – from 28 Anti-Aircraft Brigade Jun 42 |
| 66 Light Anti-Aircraft Regiment – from 56 Anti-Aircraft Brigade Jun 42; left Sep 42, later to Middle East Forces |
| 122 Light Anti-Aircraft Regiment – converted from 45 Searchlight Regiment, joined Jul 42 |
| 129 Light Anti-Aircraft Regiment – converted from 35 Searchlight Regiment, joined Sep 42 from 28 Anti-Aircraft Brigade |
| 132 Light Anti-Aircraft Regiment – converted from 85 Searchlight Regiment, joined Jun 42, to 28 Anti-Aircraft Brigade Jul 42 |