Frassineta dates back to the 10th century and was named after the widespread presence of ash trees (frassino) in the area. The village grew around a “Curtis,” an agricultural structure directed by a wealthy lord. Frassineta’s importance increased over time, and by the 13th century, it was surrounded by walls that enclosed the church, the tower, the main square, and the administrative headquarters. Craftsmen and peasants lived in the surrounding hamlets.

Located along the Via Romea, a significant medieval route connecting Northern Europe and Rome, Frassineta was a passage village for pilgrims and even barbarian armies during invasions. An Etruscan-Roman cemetery is believed to have been nearby, as large round stones found in the area were likely used as tomb markers.

Frassineta has had a tumultuous history, enduring invasions and changing allegiances between various monastic orders and ruling families. By the early 20th century, the village experienced degradation, but efforts by the Italian state and the mountain community led to its revitalization as part of the Casentino Forest National Park.