The canon law literature of the period after the Decretals of pope Gregory IX (1234) has not been investigated systematically since vol. II of the renowned manual by J. F. von Schulte (1877). The 18 papers collected in this book, originally published between 1971 and 2005, scattered in many specialized periodicals, cover a wide range of canon law texts, including prominent authors as Innocent IV, Hostiensis, Duranti. They are all drawing from a fresh assessment of the manuscript tradition and a critical review of relevant scholarship. The reprinted articles are supplemented by substantial additions and completed by a series of new Exkursus. The presentation of abundant manuscript materials makes up for a sort of reference book, which will be indispensable for any further research in the canon law tradition of the 13th and 14th centuries.