 With the unsettled conditions of Late Antiquity, the inhabitants withdrew to the defensible hilltop site that controlled the valley that communicated between Lake Trasimeno and the upper Tiber valley.Its curving concentric street system is testimony to the three encircling walls that protected the community.Like virtually all early walled villages, the Corcianesi were under the control of the bishop, in this case the bishop of Perugia, whose rights to the "castrum de Corciano" were confirmed by Pope Innocent II in 1136; Corciano appears in a list of "castelli" belonging to Perugia, 1258.