Libraries loom large in the imagination. In history, poetry, politics and science, libraries have always been sites of myth and madness, inspiration and tragic loss; monuments to both the ambitious force and the delicate fragility of human thought, imagination and expression.

The books at the Library of Ashurbanipal at Nineveh were destroyed by fire in 612 BC. Thousands of clay tablets stored there, however, survived to become the archetype of the Great Library throughout history: nursemaid of knowledge, storehouse of stories, and a crucible of language and culture.

The Library of Alexandria, founded in the third century BC, was said to have been destroyed by Julius Caesar as he pursued Pompey across the Mediterranean. In George Bernard Shaw’s 1898 play Caesar and Cleopatra, Caesar tells Theodotus, the tutor to the young Ptolemy VIII: ‘It is better that the Egyptians should live their lives than dream them away with the help of books’. Astonished, the old scholar replies: ‘What is burning there is the memory of mankind.’ ‘A shameful memory’, Caesar replies: ‘Let it burn.’ Roger S. Bagnall called Alexandria the ‘library of dreams’ due to the ‘unbearable’ ‘disparity between, on the one hand, the grandeur and importance of this library, both in its reality in antiquity and in its image both ancient and modern, and, on the other, our nearly total ignorance about it’.

The Bayt al-Hikmah (‘The House of Wisdom’) was the light of the Islamic Golden Age, a centre of astronomy, theology, philosophy and the translation of many Greek works that would later shape the course of Western history. Founded by the Abbasids in the late eighth century, it was razed by the Mongols in February 1258, forever marking the invading horde as savage, cruel and uncultured  – even if research suggests that the Ilkhanid authorities continued to sponsor scholarship after the fall of the city to Hülegü Khan.

The spectres of other libraries lost, from the libri Punici wiped out by the Romans in the Sack of Carthage (146 BC) to the thousands of pre-hispanic Mayan codices (of which just four remain) systematically burned by Conquistador priests, mark the boundary between civilisation and barbarism and the slender margins separating cultural oblivion and endurance.

Yet there are other kinds of libraries. Just as potent as the libraries that once existed are the libraries that never did. The imaginary library has never ceased to enthral poets, prelates, politicians and pranksters down the centuries.

The Bible might be the very first imaginary library. The ‘Old Testament’ is a disparate selection of several dozen (the exact figure depends on the Christian denomination) Jewish scriptures by many different authors covering vastly different topics and literary styles, composed over thousands of years, from the cosmology of Genesis to the history Chronicles; from the music and poetry of the Psalms and the Song of the Solomon to the prophecies of Isaiah, Ezekiel and Daniel. Add in the 27-book canon of biographies, letters, and apocalyptic theology making up the New Testament – not to mention the many ‘apocrypha’ steadily excluded from the canon in the centuries after Jesus’s death – and the Christian Bible starts to look less like a book and more like a library invented, a catalogue assembled amid necessity and persecution to suit the needs of a new religion.

The Index Librorum Prohibitorum (Index of Forbidden Books), the Counter-Reformation Church’s list of heretical texts, emerges like an inverted reflection of the Bible: a paranoid testament or library of unorthodoxy through the ages, continually updated with new acquisitions from its establishment in 1599 until its de facto abolition in 1966. The first Index banned not just all works by known heretics, but also ‘aeromancy, cheiromancy, physiognomy, geomancy, hydromancy, oneiromancy, necromancy, divination, magic, or astrology’, and ‘Omnes fabulae amatore’ – that is, all romances – and later included works by John Milton, Galileo Galilei, and Immanuel Kant. It may have deterred Catholic readers, but for Protestants and evangelicals it became a ‘wish list, as it were, of all the very best in contemporary theological writing’, as Robin Vose puts it in his The Index of Prohibited Books: Four Centuries of Struggle Over Word and Image for the Greater Glory of God (2022).

English dramatists also made ample use of the imaginary library. We meet the anti-hero of Christopher Marlowe’s Doctor Faustus:

Not marching now in fields of Thrasymene,
Where Mars did mate the Carthaginians;
Nor sporting in the dalliance of love,
In courts of kings where state is overturn’d
Nor in the pomp of proud audacious deeds

but ‘in his study’, ‘glutted now with learning’s golden gifts’. Surveying his personal library, Marlowe renounces ‘Aristotle’s works’ and ‘Sweet Analytics’, Galenic medicine and the code of Justinian and, finally and fatally, ‘Jerome’s Bible’. He turns instead to a darker archive: ‘These metaphysics of magicians, / And necromantic books are heavenly’, he says, sealing his doom. In Shakespeare’s The Tempest (first performed in 1611) Prospero, the usurped duke of Milan, insists ‘my library / was dukedom large enough’. These are books the sorcerer promises to ‘drown’ in exchange for his freedom from exile and the restoration of his title. In Shakespeare and Marlowe’s plays, we see that the library is always a site of potentially demonic knowledge and overweening ambition. John Dee, who owned one of early modern England’s greatest personal libraries – larger than anything at Oxford or Cambridge – was both a polymath adept at mathematics, philosophy, theology and astronomy, and an occult magician who believed he could commune with spirits – and may have supplied the model for both Faustus and Prospero.

In the 17thcentury, authors across Europe began to dream up not only imaginary libraries but fictitious books to populate their shelves. John Donne’s The Courtier’s Library or Catalogus Librorum Aulicorum Incomparabilium Et Non Vendibilium (‘Catalogue of incomparable courtly books, not for sale’, c.1604), was only discovered in 2016 when the Keeper of the Muniments at Westminster Abbey stumbled upon the manuscript entirely by accident. As Katherine Rundell says in Super-Infinite: The Transformations of John Donne (2022), this imaginary library, a satire on Jacobean courtly mores and early modern pretensions, ‘gives a key to understanding Donne’ by serving up an ‘assassin’s hit list: of intellectual sloppiness, of two-faced hypocrisy and ethical ugliness in religious debate, of the pliancy of the law and of lazy humanist scholarship of the time’. Perhaps inspired by the Bibliothèque de l’abbaye de Saint-Victor catalogued in the seventh chapter of François Rabelais’s Pantagruel (1532), Donne introduces his imaginary library with an address to the courtier looking to impress. He rails against those who seek to ‘save themselves the tedium of reading’ with a ‘taste for epitomes’. Instead, Donne playfully advises the courtier to:

hunt out books difficult for others to discover. And in conversation quote nothing from generally known authors; quote these others, so that what you say may be thought to be original if you mention no names, or, if you cite inferior works devoid of authority, people who previously fancied they knew everything may, with profound respect for you, hear of authors entirely new to them.

Many of Donne’s ‘entirely new’ and non-existent titles were ‘attributed’ to real people, including Jacobean authors, politicians and divines, which explains why he hid the manuscript. They show Donne at his most playful: The Judæo-Christian Pythagoras, proving the Numbers 99 and 66 to be identical if you hold the leaf upside down, by John Picus, was probably a satire of the Italian humanist Pico della Mirandola; Afternoon Belchings satirised the diplomat Sir Edward Hoby’s table talk; and What not? or, A Refutation of all the errors, past, present and future, not only in Theology but in the other branches of knowledge, and the technical Arts, of all men dead, living, and as yet unborn: put together in a single night after supper, by Doctor Sutcliffe viciously lampooned Matthew Sutcliffe (who founded the controversial theological college at Chelsea in 1609) and the absurdities of English theologians more generally. Yet The Courtier’s Library doesn’t just tell us about Donne’s wit, but also about how the knowledge that libraries house might be abused, distorted, or simply invented altogether. The trend was not confined to England, but found expression in the French Bibliotheque imaginaire de livrets, lettres, et discours imaginaires (Imaginary Library of Booklets, Letters, and Imaginary Speeches, 1615) and the German Catalogus etlicher sehr alten Bücher, welche neulich in Irrland auff einem alten eroberten Schlosse in einer Bibliothec gefunden worden (‘Catalog of several very old books that were recently found in a library in Ireland in an old conquered castle’).

As the ‘Age of Reason’ dawned, authors found fresh reasons to scrutinise intellectual and epistemological ambitions. Sir Thomas Browne’s Musaeum Clausum or Bibliotheca abscondita (Sealed Museum, or: Secret Library, 1684), for instance, claimed to contain ‘Rare and generally unknown Books’, paintings, and ‘ Antiquities and Rarities of several sorts’, including ‘A punctual relation of Hannibal’s march out of Spain into Italy, and far more particular than that of Livy’, Diogenes’s lost plays, Seneca’s Epistles to Saint Paul, and a botanical treatise by King Alfred the Great on Aristotle’s De Plantis (On Plants). Unlike Donne’s, Browne’s imaginary books have a whiff of plausibility, the ring of a groundbreaking discovery, perhaps nodding to the antiquarian and scientific zeal of the age. At the same time, though, he did list in his catalogue ‘A large Ostridges Egg, whereon is neatly and fully wrought that famous Battel of Alcazar’, confirming the prankster’s instinct in the imaginary librarian.

The (real) librarian and author Jorge Luis Borges’s 1941 short story La biblioteca de Babel (‘The Library of Babel’) picked up the thread, imagining the universe as an ‘endless’ library whose books contain every possible arrangement of the letters of the alphabet:

that is, all that is able to be expressed, in every language. All-the detailed history of the future, the autobiographies of the archangels, the faithful catalog of the Library, thousands and thousands of false catalogs, the proof of the falsity of those false catalogs, a proof of the falsity of the true catalog, the gnostic gospel of Basilides, the commentary upon that gospel, the commentary on the commentary on that gospel, the true story of your death, the translation of every book into every language, the interpolations of every book into all books.

Borges’s picture of the dizzying variety of his library’s catalogue mirrors its architecture: ‘an indefinite, perhaps infinite number of hexagonal galleries’. Jonathan Basile set about constructing Borges’s imagined library in the virtual realm and ‘At present it contains all possible pages of 3200 characters, about 10⁴⁶⁷⁷ books’. Is it any surprise that Borges, the master of short stories about labyrinths, mirrors, reviews of invented authors (as in ‘The Approach to Al-Mu’tasim’, 1935 and ‘Pierre Menard, Author of the Quixote’) and fictional civilisations with their own alien language, literature and philosophy (as in ‘Tlön, Uqbar, Orbis Tertius’, 1940) said: ‘The composition of vast books is a laborious and impoverishing extravagance. […] I have preferred to write notes upon imaginary books’?

Another South American author, Gabriel García Márquez, made a library of sorts central to 100 Years of Solitude (1967). The travelling ‘gypsy’ Melquíades bequeaths to the Buendía family hundreds of ‘parchments’ that remain indecipherable for a century, until Aureliano Babilonia, last of the sixth generation of the Buendías, decodes them after studying classical languages at a local bookshop-cum-library. Melquíades archive turns out to be prophecy of all that has transpired within the pages of the novel, even up to the point of Aureliano’s death, which occurs in a great storm that rises just as he works out the enigma, consumed by a tempest of knowledge.

More recent media has found in the imaginary library a convenient plot device and narrative expedient. In Harry Potter, the Restricted Section of Hogwarts Library includes titles such as Famous Fire-Eaters, Fifteenth-Century Fiends and screaming books Harry searches for in vain – alongside  Great Wizards of the Twentieth Century, A Study of Recent Developments in Wizardry and other fictional titles, for information about the (real) 14th-century French scrivener and alchemist Nicholas Flamel. The Restricted Section combines elements of the Counter-Reformation Index and the delight of early modern dramatists in the discovery of forbidden magic. Fantastic Beasts and Where to Find Them (2001) and Quidditch Through the Ages (2001) and The Tales of Beedle the Bard (2008) muddy the waters between the real and the imagined by making actual some of the fictionalised titles in the Hogwarts Library.

Libraries are also central to Star Wars. In Attack of the Clones (2002), Obi Wan Kenobi searches for information about the planet Kamino in the Jedi Archives, closely based on the Long Room at Trinity College Dublin. This library is apparently the successor to the Great Jedi Library, destroyed before the Clone Wars after standing for more than a thousand years on the remote planet Ossus. In The Last Jedi (2017), Rey tracks the exiled Luke Skywalker to a hollowed-out tree, which turns out to be a library ‘built a thousand generations ago to keep these, the original Jedi texts’, which include Aionomica, Chronicles of Brus-bu, Rammahgon, and Poetics of a Jedi. ‘Just like me’, Skywalker says,‘they’re the last of the Jedi religion.’ The influence of Nineveh endures, as the library is still seen as a vessel that alone preserves the life and learning of a civilisation under threat.

The imaginary library, then, as much as the ghosts of great ones lost, retains a powerful hold on the imaginations of authors, poets, filmmakers and, even the merchandising operations of global entertainment franchises. This appeal demonstrates the enduring enchantment of fantastical and fiendish knowledge, infinite and invulnerable archives, social critique, and impish pranks. More than that, perhaps, the imaginary library reflects back our own desire, like Aureliano Babilonia, to feed on otherworldly wisdom, browse impossible stacks, read the unreadable and find the key to unlock the perfect interpretation of truth – which, of course, can only exist in fiction.