Through a close study of local demographies and topographies, this study considers patterns of piety, charity and patronage, and by extension, the development of art and architecture in Siena's southern contado during the thirteenth and fourteenth centuries. Garrisoning the Borderlands of Medieval Siena describes Sant'Angelo in Colle as a designated 'castello di frontiera' under the Sienese Government of the Nine (1287-1355), against the background of Siena's military and economic buoyancy during the early fourteenth century. At the same time, mining thoroughly the Tax Record of 1320 and the Boundary Registration of 1318 and presenting a large number of individual records that have not been published before-including wills, tenancy agreements, land exchange and sharecropping contracts-the author constructs a portrait of the people, buildings and surrounding countryside of Sant'Angelo in Colle. Finally, adopting the methodological approach of first considering patterns of ownership of land and property in the context of identifying potential patrons of art, the study considers patterns of piety and charity established in the early fourteenth-century village and the extent to which these affected the development of the urban fabric and the embellishment of key buildings in medieval Sant'Angelo in Colle.