For anyone fascinated by how the world looked earlier in the 20th Century, maps are an absorbing and reliable window into the past. Pour over any old Ordnance Survey map, and one can discern the shape and size of the towns our midcentury forebears lived in, the routes of the A-roads they drove their now-classic cars on in the era before bypasses and motorways, and the railway lines that filled the country like arteries and veins in the pre-Beeching era. Zoom in to town plans, and layout of our living spaces comes to life: again, railways everywhere, medieval street patterns yet to be swept away by shopping centres, docks, yards and the brave new housing developments of the interwar years growing like concentric rings around the core.

With a love of maps already well-ingrained, we’d expected to while away a pleasant hour or so at the British Library’s ‘Drawing the Line’ exhibition, looking at the history of the 20th Century through maps. And we did – and that was just on the first gallery! I’m not sure quite how many maps there are in total on display across the five galleries – well over a hundred, I suspect – but each one invites close inspection to explore the story it tells. The organisation helps a lot; the galleries are thematic, mapping in turn a New World; War; Peace?; the Market and Movement. Each exhibit is concisely but usefully labelled and the maps are mounted at a level that’s easy to study for adults and older children alike (that was a huge benefit – how often has one tried to share a map spread out over a lap, or struggled to read the far end when laid out on a table). Exhibits are juxtapositioned, too, to highlight the contrasts, such as that between the maps hand-drawn from the accounts of travellers to areas like the middle east and the satellite images that lay out the territory in crystal clear detail. Similarly, differences in political or social perspectives are drawn out by comparisons between the maps of warring powers or ideologies, or between military and social cartographers.

One is constantly transported the world of the intended user – the early motorist, the First World War trench soldier, the young platoon commander in Vietnam trying to make sense of the vast jungle waiting for him. There is tragedy here – the first maps of the concentration camps smuggled out of Germany; that of a divided Berlin and of a devastated Hiroshima; but there is also joy – Tolkein’s hand-drawn map of his imaginary world, Shepherd’s depiction of Milne’s 100 Acre Wood, a 1968 map of Disneyland. Many we would have loved to have taken home as they were so good to look at (and it’s a shame that copyright issues presumably prevented the addition of a range of facsimilies to the goodies on offer in the exhibition shop). Oddly, the most disconcerting aspect of the whole exhibition is that most maps are about the same size (about arms’ length, for obvious reasons) – stand back and one is confronted by framed sheets of printed paper with little to distinguish between them. This is not like an art gallery where one can browse at a few paces’ distance; rather one has to study every item on display in detail to appreciate the story it is telling.

Favourites? Hard to pick them out, or describe them. I couldn’t help but be moved by the trench map that showed the area where my grandfather was injured in 1916, or the German reconnaissance photos of the area where I hang my hat on a regular basis. For Mrs M, some of the political maps were fascinating, particularly those depicting the principal powers as animals, spiders or octopus. Even our accompanying 12 year-old forgot the delights of the British Library free wifi, entranced by a huge map of a fantasy world featuring everything from mythical beasts to the characters from The Water Babies.

You’ve got just one month left to catch this unique exhibition – details are on the Museum’s website. Sure, there’s a great book you can buy, but you can’t beat seeing it all for yourself.

Images sourced from the web and British Library publicity for illustrative purposes only.