The Carthusians were a small monastic order founded in France in the late 11th century. Their dedication to the hermit lifestyle required a unique living situation that included individual housing for each monk, and a group of lay brothers who carried out the day-to-day tasks and interacted with the local community.This volume examines the Carthusian Order in Great Britain and Ireland from an archaeological standpoint and highlights the role of the lay brother in the everyday life of the charterhouse. Using the case studies of Witham Charterhouse and Hinton Priory in Somerset, the layouts of the lay brothers' complexes are explored through geophysical survey and comparison with Carthusian material culture assemblages from other British charterhouses. This method of investigation provides a singular view of the lay brother in medieval society and for the first time proposes a layout of an English Carthusian lower house.