This monograph presents the results of the first planned archaeological excavations in the important Italo-Greek Abbey of Grottaferrata that was founded near Rome by St. Nilus of Rossano in 1004 over the ruins of a grand Roman villa. The research focuseson the transformation of the settlement and on the social, economic and cultural dynamics from Late Antiquity to the Renaissance and it has revealed the existence of previously unknown Late Antique and Early Medieval sites. Pottery vessels made in Rome and in Southern Italy in the 11th-12th centuries and walls made of Roman spolia belonged to St. Nilus monastery. The monastery of that time had a church, a dormitory and a sort of borgo with agricultural workers dwellings, stables and warehouses. Archaeological research has also shed light on the works commissioned by Commendatory Abbots between the 15th and 18th centuries. The important results of this Research Project were also thanks to the possibility of comparing the data of Grottaferrata with those that came from the first archaeological excavations recently undertaken in Italo-Greek monasteries in Southern Italy.