Almost half a million books printed in the fifteenth century survive in collections worldwide. In Incunabula in Transit Lotte Hellinga explores how and where they were first disseminated. Propelled by the novel need to market hundreds of books, early printers formed networks with colleagues, engaged agents and traded Latin books over long distances. They adapted presentation to suit the taste of distinct readerships, local and remote. Publishing in vernacular languages required typographical innovations, as the chapter on William Caxton's Flanders enterprise demonstrates. Eighteenth-century collectors dislodged books from institutions where they had rested since the sales drives of early printers. Erudite and entertaining, Hellinga's evidence-based approach, linked to historical context, deepens understanding of the trade in early printed books.