Military maps of the Second World War

1. Introduction

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 the online Catalogue; other maps relating to the Second World War have been noted in the Summary Catalogue. However, the total of such maps represent only a tiny proportion of those preserved in the Office. 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: a search for such maps should proceed along normal archival lines.

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.

3. GSGS maps in The National Archives

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. Enquiries about the availability of these maps should be directed to the The British Library, Map Library, 96 Euston Road, London NW1 2DB, (Tel: +44 (0)20 7412 7702). There is also guidance on maps held at the British Library on the Help For Researchers section of its website.

The National Archives holds very significant quantities of GSGS mapping, but, as has been indicated above, most remain with the files, war diaries and other documents to which they relate: a search for such maps should proceed along normal archival lines. Each GSGS map is identified by a reference number and maps are often cited by such numbers. Many of the GSGS maps which have been brought to the attention of The National Archives staff are noted briefly in the card index to military map designations in the Map and Large Document Reading Room. Others may be identified under the heading 'Military Mapping' in the Summary Catalogue. The Catalogue contains a 'Map designation' field which, as it is populated over time, will facilitate the identification of references to GSGS and other military map series.

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. A set of these maps is in ZOS 3.

5. Series of records consisting entirely of Second World War military maps

6. Series of records which contain many Second World War military maps

7. War diaries

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. The war diaries are arranged for the most part by theatre of operation, as follows:

8. Military headquarters papers

Many Military Headquarters papers include maps of particular areas, often illustrating the planning and execution of operations, actions and battles. Like the war diaries, the Military Headquarters papers are arranged for the most part by theatre of operation, as follows: