While the existence of libraries in the medieval Arabic lands has been well-known, the study of specific institutions has gained in pace only over the last decade. The present article takes the Ḍiyāʾiyya Madrasa library of Damascus founded in the 7th/13th century as a case study to reflect upon the methodology of how to write the history of such a library. The history of Arabic institutional libraries has been written on the basis of catalogues and inventories. However, such documents have only been identified for very few libraries so far and it is unlikely that this approach will yield a substantial amount of further studies. In consequence, it is time to think about other approaches and this article proposes to do so on the basis of manuscript notes. The use of manuscript notes for writing this history of libraries has so far been mostly restricted to private collections. Here, we argue that manuscript notes have also an enormous potential for writing the history of institutional libraries. This approach also allows writing a much more dynamic history that does not prioritise its moment of foundation. Rather, we can look at the library as a process of continuous diachronic changes – changes that should not be conceptualised in terms of decline or deviation from the point of origin, but in terms of development and adjustment to changing historical circumstances. Writing such a processual history of libraries enables us to move away from the moment of foundation as the cardinal point and to acknowledge that the life-cycle of a library and its books over the decades and centuries involved numerous social actors well beyond the founder.