Posted on behalf of Rosalind Cotter

Figure 1 One of the ‘Principal Roads of England and Wales’ displayed in John Ogilby’s Britannia atlas. It shows the route from Newmarket in Suffolk to Wells-next-the-Sea in Norfolk. As well as towns, villages, bridges and churches, these scaled strip maps record every wood, common, ford and metal mine along the way. {credit}Wikimedia Commons{/credit}

When it comes to unearthing facts and piecing them together into a bigger picture, scientists arguably have it easier than historians. The forensic scientist has recourse to DNA, soil and pollen analyses. The astrophysicist and molecular biologist have big data and an arsenal of technology to collect and unravel it. Even the palaeontologist has a formidable taxonomic lexicon to fall back on. Historians have to make do with piecemeal facts and shadowy context, guided by sources that are often incomplete, unreliable and open to misinterpretation. They cannot systematically test their hypotheses or devise controls to shore them up.

Remarkable, then, to take a little-known seventeenth-century cartographer, shake together a kaleidoscope of disparate facts from his long life, and apply them to tease out a sinister political strategy, all carefully concealed in Britain’s first road atlas.

In The Nine Lives of John Ogilby, Alan Ereira does just that. Ereira is a master story-teller, and his biography of Ogilby (1600-76) is a riveting ride never dulled by its meticulously referenced detail. The backdrop to Ogilby’s colourful life includes the Gunpowder Plot, the English Civil Wars, the execution of Charles I, the Restoration of Charles II, the Plague and the Great Fire of London. His career encompassed the eponymous “nine lives”, as entrepreneurial lottery founder, celebrated dance master to barristers, impresario, poet, soldier and sea captain, secret agent, publisher of deluxe editions of classics and – at the grand age of 70 – Cosmographer and Geographic Printer to Charles II.

Portrait of John Ogilby (from a 1660 edition of Homer’s Illiad).{credit}Wikimedia Commons{/credit}

Of these exploits, the most fascinating (and puzzling) to a scientist is the last. The king tasked Ogilby to draw up a road atlas of England and Wales as an aid to the fledgling postal service, but this was to be much more than a simple precursor of today’s motoring guides. Using a device he dubbed a “wheel dimensurator”, a push-along wheel 5 metres (16.5 feet) in circumference that incorporated a dial to record distance, Ogilby painstakingly compiled mile-by-mile strip maps of 73 roads (see Figure 1, above). Between them, these covered 12,070 kilometres (7,500 miles). He plotted details of natural and man-made landmarks along the way at a scale of 1 inch to the mile, a mapping standard later adopted by the British Ordnance Survey until the 1970s. The distances catalogued, allowing for land contours, accord to within roughly 5% of interpolations from Google Earth.

At that time, precision measurement was equated with scientific authority. Therefore the king commandeered physicist Robert Hooke  and architect Christopher Wren, both fellows of the Royal Society, to advise Ogilby. They devised questionnaires for the project’s surveyors to ask locals as they passed through villages:  strange questions, about possible landing sites and unusual tides, watercourses and locations of farms and metal mines. No expense was spared. The eye-watering production costs, equivalent to roughly half a billion pounds today (comparable with Google’s annual expenditure on Google Maps), were at odds with the impoverished state of the country after the English Civil Wars (1642-51) and the second Anglo-Dutch War (1664-67).

The stupendous efforts of Ogilby and his surveyors and engravers culminated in a magnificent volume comprising 100 plates, Britannia, published in 1675 (its resplendent frontispiece is shown in Figure 2, below). Weighing almost 8 kilograms, it was hardly handy for travellers. The routes depicted were surprising too. Why London to Aberystwyth, a small place today and a mere fishing hamlet in the seventeenth century? And why no mention of key commercial thoroughfares such as the road to Liverpool?

Figure 2 The frontispiece of Ogilby’s Britannia. The gateway is flying the royal standard and bears the arms of the City of London. In the foreground, a map is being made by surveyors at a table of instruments. The three distant figures on the right are working with Ogilby’s measuring wheel: one is pushing it, one is cleaning the mud off, and the horseman behind is making notes and checking the direction of travel on a compass. Curiously, they are moving along a small track and not along the main highway. This and other mysteries, as well as the secret codes hidden in the plate, are discussed in The Nine Lives of John Ogilby.{credit}Courtesy of Swansea University, Information Services & Systems (ISS){/credit}

Ereira picks up on all the signs that Britannia could be a military atlas rather than a postal one, as officially designated. The routes seem to have been selected for landing marching armies, punctuated with conveniently placed metal mines for producing armaments. There were Catholic shrines marked too — surprising in a Protestant nation. Ereira’s hunch is given credibility by the secret Treaty of Dover, drawn up in 1670 by Charles II with his cousin Louis XIV of France just before the start of the Britannia project. That secret lay hidden for almost 100 years.

The Treaty stemmed from Charles’ vulnerability to covert political and religious forces across the land, after nine years in exile during Oliver Cromwell’s interregnum. Charles’ solution was to seek direct power for himself. (His inspiration was Frederick III of Denmark, who set himself up as Europe’s first monarch to rule by absolute decree after a resounding victory over the Swedes in 1660 gained him immense popularity.) First, Charles needed a glorious military victory over the Dutch, preferably funded by France. But the price for French assistance would be to shift Britain back to Catholicism. The Treaty was duly signed. Ogilby, now turned spy, was commissioned by Charles to amass the information necessary for military back-up by French troops in the event of popular insurrection. They could land unobtrusively at any of the potential invasion points identified on the map as having a functioning roadway, such as Aberystwyth or Wells-next-the-Sea.

As it turned out, no such invasion was necessary. The victory over the Dutch was modest and contributed nothing to Charles’ popularity. There was no uprising. Instead, Charles achieved absolute power by dispensing with Parliament and using the information in Britannia to remove opposition town by town. Ogilby died the year after Britannia was published — but Ereira has given new life to this extraordinary man and his meticulously compiled roadmap.

Rosalind Cotter is Nature’s Correspondence editor.

For Nature’s full coverage of science in culture, visit www.nature.com/news/booksandarts.