How to look for records of... Military maps of the Second World War
How can I view the records covered in this guide?
How many are online?
1. Why use this guide?
In this guide to military maps from the Second World War you will find advice primarily on how to find these maps among the huge collections held at The National Archives. There is, however, some advice on maps held by other archives and libraries.
Most of our maps are not viewable online and to view them you will need to visit The National Archives at Kew or pay for copies to be sent to you.
2. The origins of the maps held by The National Archives
The maps held here were those used by the War Office and the other central government departments that oversaw military operations during the war. As early as 1919, the War Office had agreed to supply mapping for the RAF and the Air Ministry. They are also maps used by the military forces themselves, some in theatres of battle, and many of them are annotated or show other signs of use and wear.
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). Senior staff members 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 Royal Engineer non-officer ranks.
GSGS operated under the Directorate of Military Operations and Intelligence which in 1936 began to map north-eastern France and Belgium at 1:50,000, though some of this work was allocated to Ordnance Survey. The Directorate’s role during the war was to supply maps to the forces, collect data on foreign survey networks, provide training, and prepare survey data for Expeditionary Force mobilisation. It was organised into small sections, each of which specialised in maps of a particular region. The War Office Map Library, which was also part of MI 4, acquired maps and cartographic intelligence data.
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 in west London and remained there throughout the war. This resulted in fragmentation of functions and records. MI 4 at Cheltenham had limited accommodation so new accommodation for MI 4/GSGS was acquired at Eastcote in north-west London. A Distribution Section was set up to handle supplies of maps to overseas expeditions. The Map Section at the Air Ministry was also under the technical supervision of MI 4 officers.
Though The National Archives holds many GSGS maps, we do not have complete or discrete sets and most are found among operational records or other wider sets of files.
3. How to search online
Though the maps themselves are not viewable online, you can use our catalogue to locate document references for maps. You will need the document reference to see the record itself. To see the maps you will have to either visit us in Kew or order copies. Bear in mind that a search in our catalogue from the catalogue homepage will also search for records in other archives around the country – keep your eye on the ‘Held by’ field to establish whether the records are here or elsewhere.
The amount of detail for each map in our catalogue varies and many maps, including those that form part of wider sets of operational records, are not described in the catalogue at all.
Search our catalogue using the following kinds of keywords and include the phrase ‘AND (map OR plan)’ after the words you are searching with:
- place name
- the name of a battle or operation
- the name of a regiment or other army unit
- GSGS number
Use the advanced catalogue search to target the records of one or more entire departments (for example, the War Office. Use the department reference, which is always a letter code, to do this (the code for the War Office is WO).
You may find it useful to look at maps alongside written records about Second World War events, strategy and operations.
Maps were given reference numbers starting with the letters GSGS and though we do not use those references in our catalogue you may find other sources refer to maps by these GSGS numbers.
4. Additional searches possible only at our reading rooms in Kew
Some Second World War maps that are not yet listed in the online catalogue are noted in paper catalogues and indexes held in our reading rooms at Kew:
- the published catalogue Maps and Plans in the Public Record Office 4: Europe and Turkey (TSO, 1998)
- card indexes arranged by place name and by military map designations (including GSGS numbers)
- a summary catalogue available at The National Archives, with separate binders arranged by place and by subject. Try looking in the subject binders under the headings ‘Military mapping’ and ‘Military operations’
Only a small proportion of the maps preserved among our records are listed in any of these catalogues. You may be able to find other maps by looking speculatively through files and volumes of textual records from the Second World War period.
5. Looking for maps within British Army operational records
Many war diaries include maps, often in the appendices. These maps are rarely mentioned in catalogue entries so you will need to search speculatively.
To find a map of a particular area, action or operation, try looking for:
- the war diary of the relevant regiment or other army unit
- the war diaries of other units known to have been in the area at the same time
- the war diaries of brigades, divisions and armies
- Military Headquarters papers
For more information about these operational records and guidance on how to search, read our guide to British Army operations in the Second World War.
6. Understanding military grid references
Many records such as war diaries, operational orders and combat reports contain grid references to locations which look like Ordnance Survey National Grid references but do not make sense when related to the National Grid.
These location references relate to a separate military grid, which was top secret during the Second World War. This grid is sometimes called the ‘purple grid’, because it was originally overprinted on Ordnance Survey maps in purple ink.
Enter keywords in the search box or browse ZOS 3 for a set of purple grid maps covering Great Britain only.
Consult the following websites which are useful for understanding and converting military grid references:
- Notes on the Modified British System of coordinates used on the European Theatre of Operations during the WWII
- FieldenMaps Co-ordinate Converter
7. Record series known to contain many military maps
Below are links to key record series that you can search within our catalogue, helping you to target your searches more precisely. By clicking on the series links you will arrive on the respective ‘series description’ pages from where you can search the series, using keywords such as the names of places, operations or battles and/or dates/years. Series description pages provide information on the arrangement of the records and sometimes some of the historical context in which they were created, as well as suggesting related series you could explore.
- WO 32 – some files include maps
- WO 106 – some files include maps
- WO 192 – includes plans of forts in the United Kingdom
- WO 208 – includes maps related to the operations of foreign armies
- WO 223 – includes maps relating to operations in France and Netherlands, and a few maps of Britain
- WO 234 – consists of maps of Crete, Cyrenaica (including El Alamein and Tobruk) and Egypt
- WO 252 – includes maps, plans and surveys of places in theatres of war worldwide
- WO 401 – includes military map catalogues and indexes from the Second World War
Other record series including many military maps are:
- ADM 234 – includes similar material to WO 252 but for naval operations
- CAB 44 – includes working copies of maps used in the Official War Histories
- CAB 106 – includes maps within military reports and dispatches
- CAB 145 – consists of maps created by the Cabinet Office Historical Section for historians writing the Official War Histories
- DEFE 2 – includes many maps relating to named operations such as Chariot, Overlord and Torch
- HO 193 – see our guide to the Bomb Census survey. Many Bomb Census maps are annotated copies of GSGS maps
- WORK 43 – includes some plans, such as Catterick Camp and the defences of Portsmouth
Records relating to air and sea operations also include maps, plans and charts. See our guides to Royal Air Force operations and Royal Navy operations in the Second World War for more information about these records.
8. Second World War maps held elsewhere
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.
Many other libraries and archives hold maps dating from the Second World War period. Use the Library Hub Discover to find maps in the collections of some major UK research libraries.
9. Further reading
Use our library catalogue to find a recommended book list.
Documentation about military surveying during the Second World War is available on the Defence Surveyors’ Association website.