The National Archives holds few discrete series of maps from the Second World War comparable to the trench maps and other operational map series from the First World War. All of the maps which have been extracted for conservation reasons are described in Discovery, our catalogue. Other maps relating to the Second World War have been noted in the paper catalogue, available in the reading rooms at The National Archives at Kew. However, the total of such maps represents only a tiny proportion of those preserved among our records. The great majority of Second World War maps in The National Archives remain with the files, war diaries and other documents to which they relate.
2. Geographical Section, General Staff (MI 4)
Most of the maps used by British land and air forces were made by the Geographical Section, General Staff (GSGS, also known as MI 4), operating under the Director of Military Operations and Intelligence. GSGS senior staff were usually Royal Engineer officers with surveying qualifications, although there were a few Royal Artillery or infantry officers. The rest of the staff were civil technical assistants and clerks, together with some RE other ranks.
In peace-time, the role of GSGS was to supply maps to the forces, collect data on foreign survey networks, provide training, and prepare survey data for Expeditionary Force mobilisation. GSGS was organised into small sections, each of which specialised in maps of a particular region. GSGS had access to the latest printing equipment. The War Office Map Library, also part of MI 4, acquired maps and cartographic intelligence data.
In 1936, the Directorate of Military Operations and Intelligence (DMO&I) began to map north-eastern France and Belgium at 1:50,000. The volume of work necessitated some being allocated to Ordnance Survey, then under War Office control.
In September 1939, MI 4 moved to Cheltenham. However, General Staff and the Map Library remained in London. In late 1940, the Map Depot moved to Alperton and remained there throughout the war. This resulted in an unfortunate fragmentation of functions and records.
As early as 1919, the War Office had agreed to supply mapping for the RAF and the Air Ministry. During the war years, the Map Section at the Air Ministry was under the technical supervision of MI 4 officers. That system was unwieldy, and was abandoned after the war. MI 4 moved to Cheltenham, and the Air Ministry Map Section moved to Harrow. Each acted independently of the other.
Because MI 4 at Cheltenham had limited accommodation, new accommodation for MI 4/GSGS was acquired at Eastcote (London). A Distribution Section was set up to handle supplies of maps to overseas expeditions.
The record set of GSGS mapping (dating back to 1881) has been transferred from the Ministry of Defence Map Library to the British Library Map Library. This includes a very large amount of Second World War material.
3. GSGS maps in The National Archives
The National Archives holds very significant quantities of GSGS mapping. Each GSGS map is identified by a reference number and maps are often cited by such numbers. Many maps with GSGS numbers are listed in our catalogue. A large number are also noted briefly in the card index to military map designations in the Map and Large Document Reading Room in The National Archives at Kew. Others may be identified under the heading 'Military Mapping' in the paper catalogue also at Kew.
Most maps within war diaries and other files have not been catalogued individually. Finding these involves speculative searches within records relating to relevant places, operations or military units. See section 7 of this guide.
Record series WO 401 includes some military map catalogues and indexes from the Second World War period.
4. Military grids
Many documents such as war diaries, operational orders and combat reports contain references to locations which look exactly like National Grid references but do not make sense when related to Ordnance Survey National Grid maps. This is because the armed services used a separate military grid, the status of which was top secret. This grid was overprinted on Ordnance Survey maps: the overprint was originally in purple and the grid came to be called the 'purple grid'. The location references in many records of the period make sense only when related to the overprinted maps.
The following websites can be useful for understanding military grid references:
5. Series of records consisting entirely of Second World War military maps
|HO 193||Ministry of Home Security: Research and Experiments Department: Bomb Census Maps.||See our Bomb Census survey research guide. Many of these are annotated copies of GSGS maps.|
|WO 234||War of 1939 to 1945: Military Headquarters Papers: North African and Mediterranean Theatres: Maps.||Maps of Crete, Cyrenaica (including El Alamein and Tobruk) and Egypt: show minefields, allied and enemy troop dispositions, lines of communication. Some are of German or Italian origin.|
|ZOS 3||Ordnance Survey of Great Britain: War of 1939 to 1945: Military Grids||The so-called 'purple grid' maps: GSGS 3907 and 3908, covering Great Britain only.|
6. Series of records which contain many Second World War military maps
|CAB 44||Cabinet Office: Historical Section: Official War Histories, Narratives (Military)||Includes working copies of maps used in the Official War Histories.|
|CAB 106||Cabinet Office: Historical Section: Archivist and Librarian Files||Maps included with military reports and despatches.|
|CAB 145||Cabinet Office: Historical Section: Official War Histories (Military): Maps||Maps created by the Mapping Section of the Cabinet Office: Historical Section for the use of historians working on official war histories.|
|DEFE 2||Combined Operations Headquarters records||A particularly rich source of maps relating to named operations - Chariot, Overlord, Torch, etc.|
|WO 32||War Office: Registered Files.|
|WO 106||Directorate of Military Operations and Intelligence|
|WO 192||Fort Record Books||Include plans of forts in the United Kingdom during the Second World War period.|
|WO 208||Directorate of Military Intelligence||Includes, in particular, maps and plans relating to the operations of foreign armies, among which those of China, Germany, Italy, Japan and Russia.|
|WO 223||Staff College Camberley 1947 Course: Notes on D-Day Landings and Ensuing Campaigns.||Various pieces in the range WO 223/115-150 contain maps relating to operations in France and the Netherlands, together with a few of Britain.|
|WO 252||Admiralty, Interservice Topographical Department, and Ministry of Defence, Joint Intelligence Bureau Library: Surveys, Maps and Reports||Contains surveys, maps, plans and photographs of places in theatres of war world-wide, compiled for strategic and tactical planning. One of the richest sources of WW2 topographical information. Similar material is in ADM 234.|
|WORK 43||Maps and Plans: Army Establishments||Include some plans from the Second World War period, in particular of the defences of Portsmouth and of Catterick Camp.|
7. Maps within operational records
Unit war diaries of the British Army often include maps, plans and tracings, usually as appendices to the narrative. When seeking a map of an area in which a particular regiment or individual served, it is often best to search the war diary of the unit in question or the war diary of another unit known to have been in the area at the date in question. Similarly, for maps of particular actions and operations, a search should be made of the war diaries of the units involved, with particular emphasis on the headquarters diaries of brigades, divisions and armies.
Many Military Headquarters papers also include maps of particular areas, often illustrating the planning and execution of operations, actions and battles.
For more information about these operational records, see our guide to British Army operations in the Second World War.