Ordnance Survey (OS) is Britain's National Mapping Agency and has been making maps of England, Wales and Scotland since 1791. Maps have been published at a variety of scales showing varying amounts of detail.
Cambridge University Library is a legal deposit library and so, with the exception of some maps at the oldest and most detailed scales (some 1:2,500 (25”) and 1:500 scale maps from the late 1800’s) Cambridge University Library Map Department should have a copy of every OS map ever published. There are exceptions but we do have a lot of them! On the whole, these cannot be found via iDiscover, so get in touch to see if we have what you want.
OS large scale (i.e. more detailed) map series fall into two categories, each with their own sheet numbering / sheet line system. If you can't find the sheet you need using the resources listed below, do get in touch with staff at Cambridge University Library Map Department:
County Series maps (published from the 1840s to the 1940s) were based on local county projections and meridians. Sheets are identified by the relevant county name plus a sheet number. These maps were published at scales of:
National Grid maps (published from the 1940s) use a national system of sheet numbering based on the National Grid. These maps were published at scales of::
For most areas there will be several editions of the maps but maps were not updated at regular intervals and the dates may vary widely between neighbouring sheets.
OS has published maps at a variety of less detailed (small) scales but the most long-lived are the 1:63,360 or 1 inch to the mile maps. The earliest of these was of Kent and was published (by William Faden but based on OS material) in 1801. Thereafter engraving and publishing was by the Board of Ordnance.
The present-day equivalent is the 1:50,000 scale Landranger series. The many different series of 1 inch maps have different sheetlines and index diagrams for these, and other small scale map series, can be found online on the Charles Close Society index diagrams web page.
For examples of 1 inch maps covering Cambridge see:
Or look at images on Charles Close Society Sheetfinder
OS no longer publish paper maps at the three largest scales (1:10,000, 1:2,500, 1:1,250).
Ordnance survey maps : a concise guide for historians by 
Old series to explorer : a field guide to the Ordnance map by 
A History of the Ordnance Survey by pdf version available on Ordnance Survey website
Ordnance Survey : map makers to Britain since 1791 by pdf version available on Ordnance Survey website
For current staff and students of the University Digimap is a key resource for digital OS (and other) maps for research and teaching. The web based resource allows you to view, annotate and print current and historic OS maps of Great Britain.
See also CULs Digimap web page
Keep up to date with what is happening with Digimap by going to the Digimap Blog, or follow Digimap on Twitter or Facebook. And see their training videos.
National Library of Scotland Map Library (NLS) has digitised many Ordnance Survey maps (though CUL has some maps that are not on the site, and vice versa). The easiest way to find them is via the Marker Pin facility (grab and move the pin to your area of interest ; maps that cover this area will appear on the right hand side ; the more you zoom in the more detailed these maps will become). Other ways to access the maps are via the Map Images page or explore other options at these web pages for: 1:2,500 County Series maps of England and Wales ; 1:10,560 County Series maps of England and Wales ; English OS town plans ; Scottish OS town plans. If you use the Georeferenced Maps option you can search for names on Ordnance Survey six-inch maps from around 1900, just use the 'Search OS six-inch 1888-1913 names' search box on the left hand side (it is in a slighter darker purple/grey box). To get the most from this site see these tips on using the site.
The Ordnance Surveyors’ Drawings, 1789-c1840, are manuscript maps from which the earliest 1:63,360 (1” to 1 mile maps) maps were derived. CUL Map Department has black and white facsimiles of some of these. The originals are in the British Library and colour images can be seen on Wikimedia Commons and on their website. Have a look at the Cambridge sheet (see also here) and the Ely sheet.
Sheetfinder on the Charles Close Society for the Study of Ordnance Survey Maps website provides links to scans of some OS maps. The website also has lots of other useful information.
Vision of Britain where the 'Historical maps' section includes small scale OS maps
British History Online 1:10,560 first edition OS County Series maps for Great Britain published 1844-1899 plus first edition 1:2,500 maps for selected cities. Also other historic maps, mostly of London
Ordnancemaps.io. Email discussion list for anyone with an interest in Ordnance Survey Maps to ask questions, assist in research, and pass on information on any aspect of Ordnance Survey maps.
Paper Ordnance Survey maps are usually bought folded since they are easier to use when out and about and easier to store. Folded maps are usually issued with covers and the study and collection of Ordnance Survey map covers provides insight into the history of OS map publishing and the evolution of OS marketing techniques but also into the art and design of different eras.
Some useful resources:
Comprehensive online gallery of Ordnance Survey map covers.
This blog entry from 2017 includes many examples of map cover art, mostly from the Ordnance Survey.
Map cover art by .jpg){kind=link}
