The hagiographical writings and spiritual genealogies (silsilat) of Sufi orders have attracted increasing levels of scholarly attention over the past two decades in the field of Islamic Studies. This body of work has established a solid foundation from which these literary and structural units can be critiqued and utilized as historical sources. This paper will intersect the discussion of these sources with an otherwise neglected element in the study of Sufi orders by examining how both their other genres of literary production, and the types of books that they collected, helped to shape their identities and personalities. The recent digitization of large numbers of manuscripts from smaller libraries in Turkey has opened up new opportunities to examine the full body of work tied to a Sufi order’s leadership. In this case, the library of the Nasuhi branch of the Halveti Sufi order, based in the Istanbul suburb of Uskudar, Turkey, has now been made available. Consisting of 301 works, along with at least a dozen others that have been scattered off into other collections around Istanbul, the library leaves us a unique source base through which we can learn about the intellectual evolution of the order as a whole from a period dating from the seventeenth century up to the advent of the modern Turkish Republic. After a full examination of all the known manuscripts in the library, several conclusions emerge. First, marginal notes by members of the order and their supporters in various unrelated works that are part of the order’s collection often help to corroborate or embellish critical hagiographical narratives in the order’s history. Second, after a thorough examination of written production by the order’s shaykhs, both before and after their accession to leadership in the order, we gain critical insights about how Sufi leaders developed the intellectual and educational background necessary to develop and serve the needs of the order’s members. Finally, the collection as a whole offers suggestive clues about how books and manuscripts played a critical role as historical characters in their own right in linking the Nasuhi shaykhs and their followers to a wider Ottoman world.