Margam Abbey was founded by the lord of Glamorgan, Earl Robert of Gloucester, in 1147. Its scriptorium was concerned not only with the usual business of a monastic house, but also provided staff for the central administration of the Gloucester earldom in the twelfth century and served as the earldom's writing-office for Glamorgan in the early thirteenth. Professor Patterson traces the organization and development of Margam's secretarial administration and analyses the nature of other similar institutions in this Marcher lordship during Margam's first eighty years. This overall picture is made possible by his identification, dating, and bureaucratic attribution of over fifty scribal hands found in the Margam manuscripts of the National Library of Wales and the charter collections of the British Library and Hereford Cathedral Library. The hands are fully described and illustrated by plates, and they show in detail the evolution of secretarial hands in the twelfth and thirteenth centuries. No similar survey exists, and this one will be welcomed not only by those working with such documents, as also by students of medieval history in a variety of fields. Robert B.Patterson is Distinguished Professor Emeritus, Department of History, University of South Carolina.