At the end of the eighteenth century, noblemen and revolutionaries spent extravagant sums of money or precious military resources competing to acquire old books, which until then had often been regarded as worthless. These books, called incunabula, achieved cultural and political importance as luxury commodities and as tools for mastering a controversial past. Men of different classes met in a new, shared marketplace, creating a competition for social authority, as books were no longer seen merely as sources of textual information but as a way of controlling the past in the service of contemporary concerns. The old books themselves were often changed to meet new expectations of what important historic objects should be. Focusing on Paris and London, but taking a resolutely pan-European view, this book examines the emergence of this commodity and of a new historical discipline created by traders and craftsmen.