Four hundred years ago, on 28 February 1615, the University Library of Groningen was officially instituted. This book celebrates the four centuries during which the Library matured from a single room with chained books to a modern and busy centre which is an information hub and a social meeting place as well. This book not only marks the Library's four-hundredth anniversary, but it also appears in a time of many changes. From September 2014, over the next few years the building will undergo a complete transformation. This is another reason why it appropriately focuses on the present-day building and the organisation's long history. The forty collections presented here form a selection of the many delightful, fascinating and rare items in our care. Together they give an impression of the treasures preserved by our Library, a trust which, it is hoped, we will continue to honour for many centuries to come.