The Roy Map is a map of Scotland that was made between 1747 and 1755. It is an incredible achievement in land surveying, and was the precursor (the origin even) of the Ordnance Survey. It has proved to be invaluable in my research on crannogs as it shows the landscape as it was likely to have looked prior to the majority of land-use changes that are associated with the ‘Improvement Period’. But in the age of GoogleMaps and GPS, the story of how the Roy Map was made is well worth remembering.

As with many innovations, the Roy Map was born out of conflict. Following the 1745 Jacobite Rebellion, it was decided that an accurate map of Scotland was desperately needed. British commanders often found themselves totally at a loss in the Scottish countryside, and the Jacobites capitalised on their local knowledge of the landscape. To counter this advantage, the British military needed an accurate map.

The task fell to one William Roy. Born in Carluke Parish, Lanarkshire in 1726, he was only 21 years old when he found himself stationed at Fort Augustus, and his superior officer put him in charge of the newly commissioned project of mapping all of the Scottish highlands. For the first two years, from 1747-1749, William Roy was the only surveyor working on the project – we can only hope/assume that he also had some untrained help. There is little information regarding Roy’s training, although it is assumed that he honed it skills as an engineer in the Board of Ordnance. In the latter years of the survey we know Roy’s attention turned largely to surveying archaeological remains, in particular the Antonine Wall. Such interest suggests that Roy was very much an ‘Enlightened Gentleman’ common to the educated class. Regardless of his training, we know that Roy was incredibly gifted in his surveyor’s skills. The first year was considered a pilot for the project, and it went so well Roy was told to continue and ‘Survey over the whole of the North of Scotland’.

Roy’s work is all the more incredible when we consider what techniques he had at his disposal. Roy’s method was to use 50 foot chains and a sighted theolodite to take measured traverses. The measurements were compiled with field notes and then drafted at a scale of 1 inch to 1000 yards to make a map. These methods were basic even by 18th century standards. An account of the survey made in the early 19th century records some more detail;

‘The courses of all the Rivers and numerous streams were followed to the source, and measured; all the Roads, and the many Lakes of Salt-water and Fresh were surveyed, as well as such other intermediate places and cross Lines were found necessary for filling up the Country; and intersections being taken to the Right and Left ascertained innumerable minute situations.’ -Arrowsmith (1806).

By 1752, all of Scotland north of the Glasgow-Edinburgh line had been finished, and it took only three more years to complete all of southern Scotland. The completed map was known then as the Great Map, but as great as it was (if you were to lay it out on a floor it would measure over 9×6 metres), very little tangible came of it. As the threat of further rebellions in Scotland waned, and the threat of French invasion in the south and dissonance in America increased, the map itself was largely forgotten. Only a handful of printed maps were ever published from the Roy Map. However, the legacy of this cartographic achievement was to be felt for a century, and culminated when the Ordnance Survey was commissioned. To this day, all the editions of the Ordnance Survey remain a treasure trove of geographic (and archaeological) information. This can, by and large, be attributed to William Roy’s skill, and as far as the archaeological information contained within the Ordnance Survey, it may just have been Roy’s influence again. He did make a point about how important he thought archaeology was in his posthumously published book about the ‘military antiquities of Scotland’.

‘Hence it is that military men, especially those have been much accustomed to observe and consider countries in the way of their profession, in reasoning on the various revolutions they have already undergone, or on those which, in certain cases, they might possibly suffer hereafter, are naturally led to compare present things with the past; and being thus insensibly carried back to former ages, they place themselves among the ancients, and do, as it were, converse with the people of those remote times.’ -William Roy (1793)