Guide

Historic Ordnance Survey maps, 1885 to 1961

Field Archaeology, a research atlas for England, lays Ordnance Survey maps from 1885 to 1961 over today's ground, from scans made by the National Library of Scotland, so a bank seen on the LiDAR can be checked against what the surveyors drew.

Last updated 25 October 2026 By Gitwix Limited

The atlas has eight old maps. Seven are Ordnance Survey maps of England, made between 1885 and 1961; the eighth, a Bartholomew map of 1940, covers Ireland only. Turn on Historic maps in Layers, choose a map by its years, and fade it over today's map, the satellite view or the LiDAR with the slider on the map.

Which historic maps are in Field Archaeology?

All eight are the National Library of Scotland's scans of its own paper sheets, fitted to the ground, joined into seamless maps and served through MapTiler.

The old maps in Field Archaeology, as the atlas lists them.
Map in the atlas	Years	Scale	Covers	What it shows
One-inch with hills	1885 to 1903	1:63,360	All of England	The wider landscape around 1900: settlements, roads, railways, parks and woods, with the hills drawn in hachures rather than contours.
Six-inch County Series	1888 to 1913	1:10,560	All of England	The second edition, field by field: roads, field boundaries, walls, streams and buildings, kinds of woodland, and antiquities.
Six-inch, every zoom	1888 to 1913	1:10,560 close up	All of England	The same six-inch sheets close up, with smaller Ordnance Survey maps of about 1900 as you zoom out.
One-inch, 1920s to 1940s	1919 to 1947	1:63,360 close up	All of England	Close up in England, the New Popular edition of 1945 to 1947, with smaller maps of the 1920s and 1930s as you zoom out.
1:25,000 first series	1937 to 1961	1:25,000	All of England	Field boundaries, footpaths and tracks, kinds of woodland, contours every 25 feet, the National Grid, and features such as earthworks, cairns and standing stones.
One-inch seventh series	1955 to 1961	1:63,360	All of England	Roads, railways, woods, towns and footpaths in colour, contours every 50 feet and the National Grid, from larger-scale surveys revised for major change in 1944 to 1948.
Five-foot town plan	1893 to 1896	1:1,056	Central London	Every building, the ground floor plans of public buildings, and the fittings of the water, sewerage and gas supply.
Bartholomew quarter-inch	1940	1:253,440	Ireland only	The whole island of Ireland at a small scale. It does not cover England.

Two of the seven show the same six-inch sheets: the Six-inch County Series layer shows them on their own, and the Six-inch, every zoom layer adds smaller maps for the distant view. Each map also has a closest zoom. Past it the atlas stretches the scan rather than leave the map blank, and the Layers panel says so. Of the maps that cover the whole of England, the six-inch maps hold their detail furthest in.

What do the six-inch maps show?

For most places, start with the six-inch County Series. The National Library of Scotland calls the series ‘the most detailed topographic mapping that covers all of Great Britain’. The more detailed 25-inch maps and town plans were not published for every area. The atlas has no 25-inch maps, and its one town plan is the five-foot plan of central London.

The six-inch maps show every road, railway, field, fence, wall, stream and building, down to mileposts and flagstaffs. They mark kinds of woodland, parks, orchards and rough ground, and parish and county boundaries. Many antiquities are marked too, sorted into pre-Roman (before AD 43), Roman (AD 43 to 420), and Saxon and medieval (420 to 1688), although the Ordnance Survey had no archaeology officer until it appointed O. G. S. Crawford in 1920.

What they leave out matters as much. Field names were dropped after 1888 and trees in hedgerows after 1892, and from 1938 new buildings were drawn in outline only, as a wartime economy. Each series had its own rules about what to show, so a feature missing from one map is not proof that it was missing from the ground.

The antiquities named on the second edition six-inch maps are also in the atlas as records. The Historic records layer holds them, from the GB1900 gazetteer made by the Great Britain Historical GIS Project at the University of Portsmouth, the GB1900 partners and volunteers, under CC BY-SA 4.0. Each has its grid reference and a Cite button.

How do I read the dates on a sheet?

The atlas shows each series as one seamless map, but each was printed as separate sheets, and every sheet has its own dates in its margin. On the six-inch County Series a sheet is named by its county and number, and a quarter sheet adds NW, NE, SW or SE: Dorset Sheet XLVII.NW is the north-west quarter of sheet 47 of Dorset. These are the dates on an Ordnance Survey sheet, and what each one means.

Surveyed: The year or years the ground was first surveyed for the sheet. The first survey of England and Wales at six inches to the mile ran from 1842 to 1893.
Revised: The year or years the surveyors went back to bring the sheet up to date. Every county was revised once between 1891 and 1914. After the First World War, upland and thinly settled areas were often not revised again until the 1950s, while towns were revised more often.
Published: The year the sheet was issued, often a year or more after the survey or revision. Some sheets were reprinted with new railways or buildings added and the old dates left unchanged.
With additions: A partial revision, usual in the 1930s and 1940s: only selected changes were added, so much of the sheet is older than its latest date.

Read them with care. The Library records the dates of a sheet on a county boundary under the first named county only, and the sheet's margin gives the rest. In the 1940s the Ordnance Survey did not always update the date of publication, so a sheet can show a revision later than its stated date of publication. The date a sheet was printed is different again: it is usually embossed in the top margin. For every county's survey and revision dates, see the Library's table of County Series dates, compiled from Richard Oliver's Ordnance Survey maps: a concise guide for historians.

To find a sheet's number and dates, search for the place, grid reference or postcode in the Library's Map Finder and open the sheet. For example, the six-inch sheet that shows Maiden Castle in Dorset is Dorset Sheet XLVII.NW. The Library holds four editions of it: surveyed in 1886 and published in 1888; revised in 1901 to 1902 and published in 1903, the second edition, from the years of the atlas's six-inch maps; revised in 1927 and published in 1930; and revised in 1938 and published in about 1947.

What is map regression?

Map regression means working back through the maps of a place, from the latest to the earliest, to see when each boundary, building, road, pond or quarry first appears and when it goes. It dates features seen on the ground, in the LiDAR or in the records, and it shows how a site came to look as it does.

Maps are among the sources a desk-based assessment should consider. The Chartered Institute for Archaeologists' standard lists ‘tithe maps, Ordnance Survey maps, estate plans’ among its sources of historic environment information, with early maps, prints and paintings.

Map regression in the atlas, step by step

Find the place by name, postcode or grid reference. If the feature is an earthwork, turn on LiDAR relief or one of the LiDAR views.
Turn on Historic maps and begin with the latest: the one-inch seventh series of 1955 to 1961 or the 1:25,000 first series of 1937 to 1961. Fade it against today's map or the satellite view.
Step back through the one-inch map of the 1920s to 1940s, the six-inch County Series of 1888 to 1913 and the one-inch with hills of 1885 to 1903. Note the first map on which the feature appears and the last on which it does not.
In Devon, go back further with the Tithe fields 1840s layer, which gives the name, owner, occupier and use of each field in the tithe survey.
Drop a pin or draw round the feature and save it. A saved mark keeps your note and the names of the layers that were on, the old map and its years among them.
Look up the sheets you relied on and cite them, as set out below.

What to watch for

Absence is weak evidence. Each series had its own rules, and smaller scales leave detail out, so compare like with like where you can: six-inch with six-inch, one-inch with one-inch.
The date on a map is the date of survey or revision, which may be years before publication, and a partial revision brings only part of a sheet up to date.
Old maps do not line up exactly with today's ground, for the reasons set out below, so allow for a small offset.
For the centuries before the Ordnance Survey, look for tithe maps, estate plans and other early maps. The Chartered Institute for Archaeologists' standard lists The National Archives, county and district archives and local libraries among the places that hold them.

How do the old maps help with LiDAR?

LiDAR shows the shape of the ground, not its history. An old map can explain a feature: a bank that follows a hedge, a lane or a quarry edge drawn in 1900 is likely to be that hedge, lane or quarry. A feature that runs across the boundaries of the old maps may be older than they are, or something the surveyors did not record, and is worth a closer look in the records and in the Historic Environment Record.

Without the use of other data sources as well it is very easy to make erroneous judgements, even if you are used to dealing with aerial photographs.

Historic England (2018) Using Airborne Lidar in Archaeological Survey, section 4.2.1

The same guidance shows a mound on LiDAR that has every appearance of a burial mound, of a similar size and shape to known barrows nearby, which aerial photographs and maps show to be the site of a covered reservoir. In the atlas, turn on an old map and the LiDAR together, and fade either one with its slider on the map to read one against the other.

Maiden Castle hillfort in Dorset in grey LiDAR relief: its ramparts ring the hilltop, with field boundaries, a farm and roads around it. — Maiden Castle, Dorset, in LiDAR relief, the Environment Agency's own hillshade. The six-inch sheet of 1903 that shows it is Dorset Sheet XLVII.NW. Environment Agency one metre LiDAR, Open Government Licence v3.0.

The same frame is drawn in eight views on Maiden Castle in LiDAR.

Why does an old map not line up exactly?

The maps were not surveyed for the accuracy of today's instruments, the paper sheets have warped over time, and each sheet was fitted to the ground on its own before the sheets were joined. The National Library of Scotland, which did the fitting, says so plainly:

Specific features on the georeferenced map layers will not always align exactly with their real-world location.

National Library of Scotland, Historic Maps API layers

The County Series adds a twist of its own. Its sheets were drawn on the Cassini projection from county points of origin, and counties with their own origin do not fit their neighbours exactly; fourteen counties of central England share the Dunnose origin, so their sheets join cleanly. In 1938 the Davidson Committee recommended recasting the large-scale maps on one national projection, which became the National Grid. From 1945 its kilometre squares were usually printed on County Series sheets, and the 1:25,000 first series and the one-inch seventh series carry them too.

So judge a feature by its shape and its place among the boundaries around it, and check it against more than one map.

How are the maps licensed and credited?

The National Library of Scotland describes these Ordnance Survey series as out of copyright: Crown copyright on an Ordnance Survey map usually lasts 50 years from the end of the year it was published. The scans and the joined maps are the Library's work, and come with its terms.

In the atlas. The Library offers the joined maps under the Creative Commons Attribution 3.0 licence (CC BY 3.0). Its one condition is a credit to the Library, with a link to its website, wherever the map is used. The atlas carries that credit on the map.
Prints from the atlas. MapTiler, which serves the maps, allows printed maps only for an internal purpose and no larger than A4, and does not allow its map content to be saved or passed on as screenshots. With an old map showing, Print a map to scale offers A4 only, and the print says it is for internal use.
Figures for others to read. For a client report, a thesis or an article, take the sheet from the Library's own map website, check the re-use licence shown beside it, and credit it as the Library asks: ‘Reproduced with the permission of the National Library of Scotland’, with a link to its map website when the work is online. Dorset Sheet XLVII.NW, for example, is marked CC-BY, the Library's label for the Creative Commons Attribution 4.0 licence.

The atlas's Sources and licences page lists the maps with their publisher and licence, and Data and licences sets out every source in the atlas.

How do I cite a historic map?

Cite the sheet you relied on rather than the atlas or the seamless map: the Ordnance Survey as author, the year of publication, the county and sheet number, the scale, the survey or revision date, and where you saw it. In Harvard style, the sheet above reads:

Ordnance Survey (1903) Dorset Sheet XLVII.NW. Six-inch to the mile (1:10,560). Revised 1901 to 1902. Available at: https://maps.nls.uk/view/101447219 (Accessed: 25 October 2026).

If you reproduce the sheet, put the Library's credit line beneath it. If you cite the map as you saw it in the atlas rather than a particular sheet, the atlas's Sources and licences page gives a citation ready to copy, and How to cite sets out the forms for every source in the atlas.

In a report, list every map you looked at, including those that showed nothing. The Chartered Institute for Archaeologists' standard for desk-based assessment says that ‘All sources consulted should be listed in the report, whether or not they have been productive.’

Questions and answers

Are old Ordnance Survey maps out of copyright?

Usually, once they are old enough. Crown copyright on an Ordnance Survey map usually lasts 50 years from the end of the year it was published, and the National Library of Scotland describes the series in Field Archaeology, the latest of them from 1961, as out of copyright. The scans are the Library's work, so credit the Library whenever you use them.

Can I use an old map from Field Archaeology in a report or a thesis?

Use the atlas to find and read the map, then take the figure from the National Library of Scotland. Prints from the atlas with an old map on them are for internal use, at A4 at most, under the terms of MapTiler, which serves the maps.

On the Library's own website each sheet shows its re-use licence. Credit it as the Library asks, ‘Reproduced with the permission of the National Library of Scotland’, with a link to its map website when the work is online.

Why are there no field names on the six-inch maps?

Because the Ordnance Survey stopped writing field names on its maps after 1888, and the six-inch maps in the atlas date from 1888 to 1913. For field names, look to the tithe surveys of the late 1830s and 1840s. In Devon, the atlas's Tithe fields 1840s layer gives each field's name, owner, occupier and use.

Does Field Archaeology have the first edition six-inch maps or the 25-inch maps?

No. The atlas has the second edition six-inch maps of 1888 to 1913. The first edition six-inch maps of the 1840s to the 1880s, and the more detailed 25-inch maps, are on the National Library of Scotland's own website.

Sources

Chartered Institute for Archaeologists (2020) Standard and guidance for historic environment desk-based assessment. Reading: CIfA. Available at: https://www.archaeologists.net/sites/default/files/2023-11/CIfA-SandG-DBA-2020.pdf (Accessed: 25 October 2026).
Great Britain Historical GIS Project, the GB1900 partners and volunteers (2018) GB1900 gazetteer. July 2018 release. Portsmouth: University of Portsmouth. Available at: https://www.visionofbritain.org.uk/data (Accessed: 25 October 2026).
Historic England (2018) Using Airborne Lidar in Archaeological Survey: The Light Fantastic. Swindon: Historic England. Available at: https://historicengland.org.uk/images-books/publications/using-airborne-lidar-in-archaeological-survey/ (Accessed: 25 October 2026).
MapTiler (no date) MapTiler Cloud Terms and Conditions. Available at: https://www.maptiler.com/terms/cloud/ (Accessed: 25 October 2026).
National Library of Scotland (no date) Copyright and reproducing map images from this website. Available at: https://maps.nls.uk/copyright.html (Accessed: 25 October 2026).
National Library of Scotland (no date) Historic Maps API. Available at: https://maps.nls.uk/projects/api/ (Accessed: 25 October 2026).
National Library of Scotland (no date) Ordnance Survey maps: six-inch England and Wales, 1842 to 1952, information pages 1 and 2. Available at: https://maps.nls.uk/os/6inch-england-and-wales/info1.html (Accessed: 25 October 2026).
National Library of Scotland (no date) Survey and revision dates for English and Welsh County Series mapping, 1842 to 1952. Available at: https://maps.nls.uk/os/county-series/dates-england-and-wales.html (Accessed: 25 October 2026).
Oliver, R. (2013) Ordnance Survey maps: a concise guide for historians. 3rd edn. London: Charles Close Society.
Ordnance Survey (1903) Dorset Sheet XLVII.NW. Six-inch to the mile (1:10,560). Revised 1901 to 1902. Available at: https://maps.nls.uk/view/101447219 (Accessed: 25 October 2026).