The medieval popes conducted a vigorous correspondence with monarchs, clergy, and lay people all over western Europe. Streams of applicants made their way to the papal court for confirmations of rights, concessions, and on some occasions to get justice. The papal Chancery was the executiveoffice, constantly on the move with the pope and the cardinals who formed the curia. Officials connected with the issue of the letters - scribes, correctors, taxators, bullators, registrars - followed the papal court. Only a small proportion of the original letters sent and received have survived.They are, therefore, very precious, not only for what they tell us about the course of events, but also for the light they throw on how papal government and administration worked. In this volume over a thousand surviving letters have been brought together, analysed, and discussed for the first time.They provide important insights not only into the activities of the papal court but also into the aspirations and desires of the petitioners.