Most medieval manuscripts are now held in specialist libraries, but a century ago there was a flourishing international trade in such books, with London at its centre. The first half of the twentieth century saw new record auction prices and many manuscripts leaving Europe for the USA, but also periods of economic depression and social and political upheaval in which both the economic and cultural values assigned to manuscripts were reassessed. The trade in this period determined the physical destination of many manuscripts, and helped set the direction of scholarship. This book examines the trade in hand-written books produced before ca. 1500 and its impact, from the death of the designer, socialist, and manuscript collector William Morris in 1896 to the Second World War.