The Ordnance Survey was established in Tudor times, originally called the Board of Ordnance - a military organisation whose purpose was to manage armaments for the army and maintain national defences. Facing the threat of invasion, and with instruction from the Government, the Board's engineers and draftsmen set out to produce military maps.
These Surveyor's Drafts represent the first comprehensive survey of England since Saxton's mapping in the 1570s. After the Battle of Trafalgar in 1805, the survey was extended from just the south of England, to cover most of the country. The draft maps were produced at different scales depending upon the military significance of the area. Places deemed to be important were surveyed at a larger scale.
The surveys to produce these maps were carried out between 1780-1840.
The military necessity of these maps is reflected in the features they surveyed. The draftsmen were concerned with mapping woodlands which could provide cover for ambush, for example and the contours were drawn on terrain that might offer tactical advantage in battle. Particular attention was also paid to communication routes, such as roads and rivers, which were mapped very accurately.
Kent was the first county to be surveyed as part of the OSD - beginning in 1795, the final draft was published in 1801. All of the maps were assembled at the Tower of London, where the scale was reduced to one inch to a mile and they were engraved on copper plates for printing.
Extract from First edition OS, David & Charles map sheet 87
This article is summarised from the British Library: