If you want to see what your town looked like 50 years ago, or even 150, the Map Room can find you a detailed Ordnance Survey map to answer the question. And if you want a really large scale plan showing the same site in the present day, you can buy one via an agent for OS Mastermap. But what about the period in between?

The OS map extract above shows Stratford-upon-Avon in 1889 at a scale of 1:2500. Maps at the same or larger scales continued to be published, updated at intervals, until the late twentieth century. In the 1990s, the OS stopped producing printed maps at the largest scales of 1:10,000, 1:2500 and 1:1250. Present day large scale mapping continued to be produced in digital format, and could still be purchased, but each time the data was updated the previous version was lost. There was a danger that recent history would disappear into a black hole. If a researcher in 2022 wanted, for example, an OS Mastermap of Kendal from 2012, what would they do?

The Legal Deposit Libraries – of which the Bodleian is one* – sprang forward to fill the breach. Working with partner organisation thinkWhere, they negotiated a scheme for the OS to deposit an annual digital “snapshot” of large scale mapping across the whole of Great Britain from 1998 onwards. Northern Ireland, which has its own mapping agency, soon followed suit. The dataset is updated annually. It was an early example of electronic Legal Deposit, preceding the official eLD which began in 2013.

What is electronic Legal Deposit? Under Legal Deposit legislation the Bodleian Libraries, and the other LDLs,  are entitled to a copy of every item published in the UK. Legal Deposit of printed materials has existed in some form since 1662, and thousands of the books, maps, serials, and printed music items in the library are here as a result. Electronic Legal Deposit was based on this; it came into force in 2013 and since then many published items have been deposited in electronic rather than print format. You can read more about it here on the Electronic Legal Deposit Libguide. In most cases, electronic Legal Deposit items are listed on SOLO and can be read on any Bodleian Library reading room computer.  Maps deposited on electronic Legal Deposit usually require specialist viewing software, and can be seen on a dedicated terminal in the Rare Books and Manuscripts Reading Room of the Weston Library. You can log in using your Bodleian Libraries username and password. Extracts can be printed using your PCAS account.

This has recently been updated with a much wider range of maps; as well as the large scale OS maps described above you can see a whole array of different maps of the UK here. There are detailed town plans by XYZ Maps and The Clever Little Mapping Company, large scale coastal charts by Antares, and a wealth of cultural information. There is information from Historic England showing locations of all the listed buildings geographically plotted with links to the website, descriptions and images; Historic Environment Scotland and Welsh preservation organisation CADW show similar information for Scotland and Wales. Also included are World Heritage sites, protected monuments, battlefields and shipwrecks.  The map below shows the locations of listed buildings in Portsmouth.

The maps so far are almost exclusively for areas within the British Isles, but the system is set up to give access to maps from anywhere in the world via a map interface. As an increasing amount of publication is now digital rather than printed, this can only grow.

*The other LDLs are the British Library, National Library of Scotland, National Library of Wales, Cambridge University Library and Trinity College Dublin, in case you were wondering.