GSGS 4250: British Army Map Series of France (1:50,000)

The GSGS 4250 (named for the Geographical Section, General Staff designation 4250) was a British Army topographic map series at 1:50,000 scale, produced by the Ordnance Survey during the Second World War between 1941 and 1944. Created for operational use, it provided detailed coverage of much of France, particularly the north-western regions central to the Allied campaign.

These maps were instrumental in planning and executing military operations, most notably the Normandy landings and subsequent liberation of France. Many sheets were carried by Allied forces on D-Day, and today they serve as a valuable resource for military historians and those researching family connections to the conflict. We have digitised many of these maps with high-resolution scans from original wartime editions, including full coverage of the landing areas. These are now available to explore in our online archive.

Online GSGS 4250 Map Index

This section provides a list of all known GSGS 4250 maps that are freely accessible online. It includes many maps digitised for the Normandy War Guide archive as well as others from public collections such as the US National Archives. This unified interface allows you to browse all known online editions of GSGS 4250 sheets in one place.

Key to Sources: NWG – Normandy War Guide, USNA – United States National Archives, CGNL - Collectie Gelderland

Map Features

Each GSGS 4250 map sheet provides a detailed topographic view of the landscape with 10-metre contour lines to depict elevation (plus spot heights for key peaks). Major and minor roads are depicted in up to five classifications (from main routes to tracks), and railways in two categories

Towns, villages, and other settlements are shown with their names, and various symbols indicate features like woods/forests, rivers, canals, and bridges

An overprinted military grid system (based on the French Lambert Conical projection) is present on all sheets, enabling users to determine precise coordinates or “map references” – crucial for artillery, navigation, and referencing positions in war diaries.

The map sheets include marginal information like a glossary of French terms, an index to adjoining sheets, and a reliability diagram (indicating which areas were updated from air photos), reflecting the fact that these maps were produced under wartime conditions and updated whenever new intelligence became available

The series was based primarily on enlarged French 1:80,000 "Carte d'État-Major" sheets produced by the Service Géographique de l’Armée. These were adapted and updated by British cartographers with aerial reconnaissance and other intelligence where available to update roads, towns, and other details.

GSGS 4250 maps provided Allied soldiers with up-to-date tactical maps that balanced French topographical detail with Allied requirements – albeit sometimes at the cost of perfection, as the rush of wartime production led to occasional spelling errors, ambiguities, or inaccuracies in less critical details.

A Map’s Second Life: Envelope from a GSGS 4250 Sheet

An example of postwar reuse is this envelope, postmarked 21 December 1948, made from a GSGS 4250 map sheet. During the immediate postwar period, surplus maps were sometimes repurposed for practical uses, such as packaging or stationery. The envelope shows visible portions of the original topographic map, offering a small but tangible glimpse into how these documents continued to circulate beyond their intended military function.

American Printings: AMS 762

In addition to British printings, the United States Army Map Service (AMS) produced copies of GSGS 4250 maps under the designation AMS 762. These were largely identical in content and layout, and were produced in part to expand printing capacity and support Allied operations in shared theatres. The Caen sheet, for example, exists in both a British GSGS 4250 edition and a U.S. AMS 762 printing, with only minor differences in marginalia and print formatting.

An example of the American AMS 762 printing of the Caen sheet is also available to view in the online archive

Coordinate Converter

The GSGS 4250 series uses a British-modified military grid based on the French Lambert Conical projection. To assist with locating positions referenced in wartime documents or war diaries, you can use the WW2 Coordinate Converter. This tool allows you to convert military grid references from GSGS 4250 maps into modern latitude and longitude or overlay them on contemporary basemaps. Much of the invasion area is covered by a more accurate, true-to-map conversion.

Grid references often appear in war diaries and operational reports in formats such as Sheet 7F/1 9677, vT9677, 9677 975775

Phil – founder of Normandy War Guide
I started the site more than a decade ago after my first trip to Normandy and have been hooked ever since. I visit a few times each year to explore new sites and update the guide. Over the years I've also transcribed thousands of WWII war diaries and scanned original maps to keep this history accessible for everyone.