The Benedictine Bernhard Pez (1683–1735) of Melk and his brother Hieronymus (1685–1762) were two of the most eminent historiographers of the baroque era. However, only a small number of their studies on medieval manuscripts, undertaken above all in Southern Germany and Austria, were included in the anthologies published during their lifetime. A history of the literature of the Benedictine order (Bibliotheca Benedictina Generalis) as planned by Bernhard Pez was never finished. Copies of medieval manuscripts that he and others made for this project are still held in the library of Melk Abbey. In the nineteenth century, most of these documents and materials were bound into 60 codices. The present volume presents the first detailed description of these manuscripts. The catalogue focuses on identifying the exemplars, scattered all over Europe, that were used for these copies in Melk. The publication will be of interest to historians, philologists, theologians and librarians.