The building is characterized by an ancient tradition - of which we have news since the fourteenth century - with the house where, towards the middle of the twelfth century, Galgano, holy knight and hermit of Chiusdino, was born.
Having received the house as an inheritance from the saint's mother, the Cistercian monks of the Abbey of St. Galgano began its refinement in memory of the saint.
In the fourteenth century the monks took over the secular brotherhood (or community) named after the saint, to whom we owe, in all probability, the commissioning of a cycle of frescoes created in the second half of the century by a Sienese artist, of which some significant fragments have resurfaced. Other interventions to increase the cult of patrons were carried out in 1801, when the brotherhood was expropriated by the French troops, who reduced the building to a barracks and used some rooms as a prison. Then, after having been used by the municipality of Chiusdino in 1900, the Confraternity restored the chapel in the basement - completed in 1905 - and reopened it for worship.
Facing the entrance portal from the outside, a relief by Giovanni di Agostino depicts St.
Galgano led by Michael the Archangel on the Montesiepi hill; the work was built around 1330; the one currently on display is a copy, while the original is kept in the Civic and Diocesan Museum of Sacred Art. In the small chapel, on the left wall, the remains of the fresco cycle; on the right, the boulder on which, according to local tradition, the saint's horse would have been nursed when the Archangel Michael appeared and left imprints of his knees on it; the stone was brought here in 1958 from its original location along the path between Chiusdino and Luriano.