The defining characteristic element of the Sacra di San Michele is its position on the top of Mount Pirchiriano, a rocky spur belonging to the group of Rocciavré in the Cottian Alps (altitude 962 meters). Pirchiriano is the very ancient name of the mountain; an elegant form of the word “Porcarianus” or “mountain of Pigs”, and thematically linked to the neighbouring peaks “Caprasio”, or “mountain of Goats”, and “Musinè” or “mountain of Donkeys”.
The mountain bears evidence of human settlements since prehistoric times. In later times, it was fortified by the Ligurians and by the Celts under the rule of the two kings Cozio. In 63 A.D., when the Cottian Alps become a Roman Province, the peak’s strategic position was exploited by the Romans for military purposes, with the establishment of a “castrum” (garrison). In 569 A.D. the Longobards invaded and occupied the Cottian Alps. In this period, they built the famous “Locks of the Longobards” in the Susa Valley. They raised walls and towers across the valley when, under the leadership of their king Desiderius and his son Adelchi, they rallied to repel the entry into Italy of Charlemagne, king of the Franks. In 773 A.D., the Franks, victors of the “Battle of the Locks”, conquered the area and remained there until 888 A.D., when the Saracens invaded the western Alps and ruled for about eighty years.
"Around the end of the tenth century St. John Vincent, a disciple of St. Romuald, began to live the life of a hermit here. The choice of the place is certainly conditioned by its impressive setting, by the predisposition to the sacred of Mount Pirchiriano and by the pre-existence of a colony of hermits on Mount Caprasio. On the threshold of the year one thousand, a man who sought redemption from a questionable past burst into John Vincent’s hermitage: he was the Count Hugh (Ugone) of Montboissier, a rich and noble Lord of Auvergne, who had gone to Rome to ask forgiveness from Pope. The Pope gave him by way of penance a choice between a 7-year exile and the task of building an abbey. It was in the years 983-87 when the building of the monastery began, five Benedictine monks were assigned to establish the community. A staging point for high social level pilgrims developed on Pirchiriano, making it an international cultural centre, through the initiative of Hugh of Montboissier and his systematic recruitment of abbots and monks in Auvergne. Since its foundation, the monastery vigorously sought from the jurisdiction of the bishop of Turin: in particular, in the eleventh century the monks came out clearly in favour of Roman centralist reform, under their most famous abbot Benedict II. This autonomy from temporal and ecclesial authority was quickly attained and the abbey, thanks to its wide and generous hospitality, was able to stimulate exchanges of ideas not only in matters of practical order but also in matters of deep spiritual significance, which helped to create our common heritage of a great religious civilization. It was in this period that the Sacra extended its possessions in Italy and Europe, over which it exerciseed spiritual, administrative, civil and jurisprudential rights. From the beginning until about the midpoint of the fourteenth century, the monastery enjoyed its most celebrated era under the leadership of Benedictine abbots, after which followed a half century of decline. In 1379 the misgovernment of abbot Peter of Fongeret led Count Amadeus VI of Savoy (the Green Count) to ask the Holy See for the abolition of the office of the abbot monk, which was replaced by a commendatory abbot. With the appointment of a commendatory a period of sufering began in the monastery: from 1381 to 1622 the monks were governed by priors, with the commendatory abbots."