In his capacity as precentor of Malmesbury Abbey, William was also its librarian. As expressed in the passage from his Gesta Pontificum quoted above, he had, to his knowledge, supplied the abbey with more books than any of his predecessors. This paper studies that accomplishment from two perspectives. Surveying the corpus of William's extant autographs, I shall first attempt to characterise his objectives with regard to the production of books for the library of his house. Scrutinising one of his autographs in a more detailed manner, I shall then observe how he approached and used his sources when copying books with the assistance of his scribes. These two discussions are in essence commentaries on the quoted extract, and together they seek to form a concise account of how William performed his duty to collect books as librarian.

His hand has been detected in twelve manuscripts. Of these, he was the sole scribe for two, and he collaborated with other scribes for the remaining ten. The two manuscripts by him alone contain the Collectio Canonum Quesnelliana, an early collection of conciliar decrees, and a working copy of his Gesta Pontificum. The remaining ten books include three volumes of ancient classics, two of patristic texts (including William's original collection of extracts from the works of Gregory the Great), two containing works by two medieval philosophers (one Carolingian and one contemporary), an anthology of biblical exegesis, a collection of extracts connected to Roman history from Troy to William's day, and a collection of computistica.

To what extent are these twelve survivors representative of the whole corpus of books made under William's supervision in his role as librarian?