Throughout history, we’ve used maps as works of art, scientific models of the world, and visual metaphors. But how did cartography come to play such a central role in our daily lives? That’s precisely what Simon Garfield explores in On the Map: A Mind-Expanding Exploration of the Way the World Looks (UK; public library) — a fine addition to these favorite books on maps, peering into the roots of modern mapmaking through trivia-like factlets and curious historical anecdotes.

In fact, the story of our infatuation with maps is as much a story of scientific ingenuity as it is of artistic acumen and clever marketing, with a side of evolutionary biology to boot. And it all began with ur-astronomer Ptolemy, who lived in the second century AD and spent the majority of his life studying at the Great Library of Alexandria. Garfield writes:

Ptolemy’s Geographia … was a two-part interpretation of the world, the first consisting of his methodology, the second of a huge list of names and cities and other locations, each with a coordinate. If the maps in a modern-day atlas were described rather than drawn they would look something like Ptolemy’s work, a laborious and exhausting undertaking, but one based on what we would now regard as a blindingly simple grid system. In the seventh section of Geographia (there were eight in all), Ptolemy provided detailed descriptions for the construction of not just a world map, but twenty-six smaller areas. No original copies have survived, and the closest we can get to it is a tenth-century Arab description of a colored map — though whether that was an original or merely inspired by his text is unknown, and at any rate, it no longer exists.

The influence of Ptolemy’s world map, which went on to become one of 100 diagrams that changed the world, was monumental. But, lest we forget that cartography reflects political power structures and propaganda, Ptolemy’s map was full of geopolitical inaccuracies:

As one would expect, Ptolemy had a skewed vision of the world. But while the distortion of Africa and India are extreme, and the Mediterranean is too vast, the placement of cities and countries within the Greco-Roman empire is far more accurate. Ptolemy offered his readers two possible cylindrical projections — the attempt to project the information from a three-dimensional sphere onto a two-dimensional plane — one ‘inferior and easier’ and one ‘superior and more troublesome.’ He gives due credit to a key source, Marinus of Tyre, who had advanced the gazetteer listings system a few decades earlier, assigning his locations not merely a latitude and longitude, but also an estimated distance between them. (Marinus had another claim, too: his map data was the first to include both China and the Antarctic.)

Rather than lamenting his inaccuracies, however, Ptolemy embraced them as an opportunity to exercise his imagination, which introduced an element of opportune serendipity to early explorers’ journeys:

Ptolemy boasted that he had greatly increased the list of cities available to the cartographer (there were about 8,000), and also disparaged the accuracy of Marinus’s measurements. But he had his own flaws. Indeed, the map historian R.V. Tooley suggests that Ptolemy stood apart from his predecessors not just in his brilliance but in his disregard for science. Where earlier cartographers were willing to leave blanks on the map where their knowledge failed, Ptolemy could not resist filling such empty spaces with theoretical conceptions. … [T]his had the uncanny ability to send ambitious sailors, Columbus among them, to places they had no intention of seeing.

But instead of the boon of mapmaking one would expect after Ptolemy’s innovations, the world fell into what Garfield calls “the cartographic dark ages” for about a thousand years. Both the Romans and the Byzantines failed to advance Ptolemy’s work, and it wasn’t until the rediscovery of Ptolemy’s atlas and its translation from Greek into Latin in 1450s Venice that the modern cartographic vision of the world was finally born — and, along with it, our obsession with maps.

Indeed, what sparked that cultural love affair was an unexpected feature we, with our characteristic presentism bias, have come to see as distinctly modern: DIY customization and the personalized map. Half a millennium before Mapalong and Findery, custom atlas books gave rise to the mapping revolution. Garfield writes:

It was in Venice that the atlas became a craze. In the 1560s mapsellers had the idea of allowing customers to build their own atlas from the stock on display. If you didn’t like the Spanish maps on offer, you simply didn’t put them in your book. But if you were intrigued with the emerging face of South America you could choose two or three (perhaps conflicting) impressions. Most buyers would select one single-sheet copy of the latest work of the leading cartographers — Giacomo Gastaldi was strong on Africa and Arabia, whilst you might choose Paolo Forlani for South America and George Lily for the British Isles. These would then be folded and bound between covers of your choice, a unique and discerning collection, the cartographic iPod of its day.

But, Garfield argues, the cultural role of maps extends far beyond Renaissance merchandising tricks and well into our very evolutionary development. He cites the work of Richard Dawkins, who has argued in Unweaving the Rainbow that primitive mapping allowed hunter-gatherers to communicate their tracking plans before the development of language:

A tracker would be ‘fully accustomed to the idea of following a trail, and imagining it laid out on the ground as a life-size map and the temporal graph of the movements of an animal. What could be more natural than for the leader to seize a stick and draw in the dust a scale model of such a temporal picture: a map of movement over a surface?’ This, of course, is also the beginning of cave paintings — humans and animals depicted in their daily round of survival, with representational figures standing for something else, and introducing the concept of scale and directional arrows and spatial difference. But as for the brain, we may have found the reason for expansion and sophistication. Richard Dawkins concludes with a question: ‘Could it have been the drawing of maps that boosted our ancestors beyond the critical threshold which the other apes just failed to cross?’

The rest of On the Map goes on to explore such fascinating facets of cartographic history as the gender bias in how maps are made, FDR and Churchill’s quest to design the perfect globe, how Lord Byron popularized the term “guidebook,” and what breakthroughs in neuroimaging tell us about the brain’s unique capacity for spatial orientation.