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.