Occult? Try upstairs! Inside the world’s weirdest library, now open to the public

A mysterious cosmic emblem hangs over the entrance to a building in Bloomsbury, at the heart of London’s university quarter. Depicting concentric circles bound by intertwined arcs, it represents the four elements, seasons and temperaments, as mapped out by Isidore of Seville, a sixth-century bishop and scholar of the ancient world, as well as patron saint of the internet. What lies within is not a masonic lodge, though, or the HQ of the Magic Circle, but the home of one of most important and unusual collections of visual, scientific and occult material in the world. Long off-limits to passersby, the Warburg Institute has now been reborn, after a £14.5m transformation, with a mission to be more public than ever.

“We are essentially devoted to the study of what you would now call memes,” says Bill Sherman, director of the Warburg. To clarify, the institute is not a repository of Lolcats and Doges, but of global cultural history and the role of images in society, with a dazzling collection ranging from 15th-century books on Islamic astronomy, to tomes on comets and divination, not to mention original paintings used for tarot cards (about which a show opens here in January). At least half of the books can’t be found in any other library in the country.

The institute was founded in Hamburg at the turn of the 20th century by pioneering German art historian Aby Warburg, whose work focused on tracing the roots of the Renaissance in ancient civilisations, mapping out how images are transmitted across time and space. Long before the algorithms of today’s digital world, he drew unlikely connections between different epochs, regions and media, putting his findings into a sprawling visual diagram of European art. Named the Bilderatlas Mnemosyne, it was a kind of analogue internet of photos, reproductions and newspaper clippings pinned to boards, comprising 1,000 images on 65 panels each one metre tall. Unsurprisingly, it was incomplete by the time of his death in 1929.

Warburg hailed from a wealthy Jewish banking family, so when the Nazis came to power in the 1930s, his institute, its staff, and most of the furniture, were evacuated to Britain. The organisation, with its 60,000 books and 10,000 photographs, became part of the University of London, housed in a building designed by Charles Holden in the 1950s, where it has been ever since. But it has never had much of a public face. It has been an essential resource for artists and scholars for decades, but few outside the rarefied ranks of researchers knew the Warburg was there.

“I cycled past this building for years without knowing what was inside,” says Elizabeth Flower of Haworth Tompkins, architects of the overhaul. Having worked on the transformation of the London Library and the V&A’s Clothworkers’ Centre, the architects were well placed to bring their knack for light-touch surgical intervention here. Along with essential upgrades to heating, lighting and energy performance, the project has given the institute a public, museum-grade gallery for the first time, as well as a new auditorium, deftly inserted into the U-shaped courtyard, to host public lectures, conferences, concerts and films.

Where once visitors were greeted with an off-putting glass screen and security desk, a new welcoming entrance leads you through to the gallery, where an opening exhibition charts the journey of the institute, alongside artist Edmund de Waal’s Library of Exile of books by exiled authors. Windows from the entrance foyer provide views down into the new archive reading room – giving a glimpse of the previously hidden inner workings of the institute – and across to the auditorium, which appears to float in the white-tiled courtyard, illuminated by light-wells either side.

Conceived as the new heart of the place, the lecture theatre is an atmospheric space, lined with warm timber ribs and topped with an elliptical concrete roof light, modelled on the original Warburg Bibliothek reading room in Hamburg. It has a hint of Dr Strangelove, ready to host the high council of wizard-researchers. The ellipse was an important symbol for Warburg, representing concepts of freedom and continuous oscillation between thought and research.

“It’s exactly the path our design process followed too,” jokes Flower, recounting the endless circles of options that were considered before the complex 3D jigsaw of rearranging the institute’s spaces was resolved. Advice even came from Albert Einstein: a sketch he sent to Warburg, displayed in the exhibition, shows his calculation of the elliptical orbit of Mars, on which the ceiling was based, adding a further celestial aura to this cosmic place.

The scale of ambition of this meticulous revamp was in part prompted by a threat. In 2014, the Warburg made headlines when a long-running, costly legal battle with the University of London over the institute’s future reached the high court. Both sides declared victory, with the Warburg’s independence and funding ultimately safeguarded by the ruling. In 2016, the university allocated £9.5m for a basic refurbishment of the building, which was then increased by £5m of fundraising, and the scope expanded to the present brief.

The result makes Holden’s building look better than ever. Suspended ceilings have been removed, blocked windows opened up, bringing natural light into the library (harmful rays safely filtered by UV film), and woodblock and terrazzo floors restored to their former glory. Fluted timber columns in the reading room are complemented by new sapele joinery that echoes Holden’s style, while harsh strip lights have been replaced with in-keeping globes and the collection space extended to allow for at least 20 years’ future growth.

The expansion has also enabled the full reinstatement of Warburg’s unique cataloguing system, with four floors each dedicated to Image, Word, Orientation and Action – “uniting the various branches of the history of human civilisation,” as his close collaborator, Fritz Saxl, put it, breaking culture free from the confines of its usual disciplinary silos. There are few other libraries in the world where you might open a drawer of photographs marked Gestures, to find thematic folders labelled Fleeing, Flying, Falling, along with Denudation of breast, Grasping the victim’s head, and Garment raised to eyes (Grief). Warburg’s unusual system might not have caught on elsewhere, but it still provides a powerful way for artists, writers and researchers to make unexpected connections and pursue fertile tangents – preceding our world of swiping through hashtags, links and recommended feeds by a century.

“It’s a building filled with literal magic,” says novelist Naomi Alderman, who has spent much time writing here. “A place to sit amid books that are almost definitely emanating auras of sorcery … One brief stroll through the shelves and I always find some new wyrd inspiration.” The reading rooms themselves are still limited to card-carrying researchers, but through the new exhibition and event programme, the public can finally get a taste of Warburg’s weird and wonderful world for themselves.