Most expensive book (private sale)
Sherborne Missal
24,560,000 US dollar(s)
United Kingdom ()

The most expensive book acquired through a private sale is the Sherborne Missal, a richly-illuminated liturgical text made at Sherborne Abbey in Dorset, UK, in the early 15th century. The missal was transferred to the British Library in August 1998 by Ralph Percy, the 12th Duke of Northumberland, as part of a deal settling the inheritance tax due on his late father's estate. The book was valued at £15 million ($24.56 million). A total of £9.4 million was the value accepted as "Payment in Lieu" for the Duke's outstanding tax bill, while the remaining 5.6 million was covered by the Heritage Lottery Fund and the British Library.

A missal is a book that provides instructions and relevant texts that a priest needs to conduct mass throughout the liturgical year. This particular example was commissioned by Robert Bruyning, Abbot of the Benedictine Abbey of St Mary in Sherborne, Dorset, UK, and made between 1399 and 1407. The principal scribe was a monk at the abbey called John Whas, who identifies himself in the colophon (it says "John Whas, the monk has worked to write this book, and rose early, his body becoming much wasted in the process"). The lead artist was a Dominican friar called John Siferwas, who inserted references to himself – including a coat of arms and several self-portraits – throughout the book's many illustrations.

The Sherborne Missal is an opulent show-piece intended to demonstrate not only Bruyning's godliness, but also his wealth, power and political connections. He is pictured more than a hundred times throughout the book, often wearing ostentatious and elaborate vestments; he is also shown with hunting hounds and in the company of powerful bishops and landowners.

The Sherborne Missal has been described as the "unrivalled masterpiece of English book production in the fifteenth century" by historian Kathleen Scott.