The Private Case of the British Library is a collection of pornographic books and other items, not normally available to general readers. The collection is similar in purpose to the Enfer, at the Bibliothèque nationale, the Δ (Greek Delta) collection in the Library of Congress and the Φ collection (Greek Phi) at the Bodleian Library.
The Private Case was established in 1857 and the core of the collection is the bequest of the Victorian collector Henry Spencer Ashbee in 1900 to the British Museum. Other significant contributions include bequests by Charles Reginald Dawes and Beecher Moore, both in 1964. None of the items in the collection have been purchased or acquired via copyright deposit. In 1981 Patrick J Kearney compiled a bibliography of the 1,914 significant books in the Private Case. which includes a substantial introduction by American social critic and folklorist Gershon Legman. The collection contains works by notable figures in the world of written erotica including The Earl of Rochester, the Marquis de Sade and William Simpson Potter.
In recent years the British Library has dispersed much of this material formerly kept in reserve into the main collections.