This volume was conceived with the double aim of providing a background and a further context for the new Dumbarton Oaks English translation of the Life of St Neilos from Rossano, founder of the monastery of Grottaferrata near Rome in 1004. Reflecting this double aim, the volume is divided into two parts. Part I, entitled “Italo-Greek Monasticism,” builds the background to the Life of Neilos by taking several multi-disciplinary approaches to the geographical area, history and literature of the region denoted as Southern Italy. Part II, entitled “The Life of St Neilos,” offers close analyses of the text of Neilos’s hagiography from socio-historical, textual, and contextual perspectives. Together, the two parts provide a solid introduction and offer in-depth studies with original outcomes and wide-ranging bibliographies. Using monasticism as a connecting thread between the various zones and St Neilos as the figure who walked over mountains and across many cultural divides, the essays in this volume span all regions and localities and try to trace thematic arcs between individual testimonies. They highlight the multicultural context in which Southern Italian Christians lived and their way of negotiating differences with Arab and Jewish neighbors through a variety of sources, and especially in saints’ lives.