The dispersal in 1812 of the library of John Ker, Duke of Roxburghe (1740–1804) was the bibliographical event of the decade and a key moment in 'bibliomania'. The huge collection contained illuminated medieval manuscripts, incunabula, fifteen books printed by Caxton, and all four Shakespeare folios. The sale, orchestrated by the bookseller and auctioneer Robert Harding Evans (1777–1857), attracted the greatest book collectors and dealers of the day, setting new records. For the first time in British auction history a single book fetched more than £1,000, while the Valdarfer Boccaccio, the first edition of the Decameron, sold for £2,260. Reported in The Times, the sale immediately gained mythological status. Reissued together here are the printed catalogue and its supplement, both annotated by an attendee at the auction who recorded the name of every buyer and the price paid for each book. Ed Potten, Head of Rare Books at Cambridge University Library, has provided a new introduction that places the catalogue in its wider context.