SAGRA DI SAN MICHELE - Popular name of an ancient Benedictine abbey, in the diocese of Susa, built on a spur (Monte Pirrichiano, 916 m.) at the entrance to the Susa Valley, near the place where Desiderius blocked Charlemagne’s advance (the true name is S. Michele delle Chiuse; in the Middle Ages it was called coenobium Clusinum).
Its origins go back to the end of the 10th century, when Hugues le Decousu de Montboissier, a nobleman of Auvergne, was ordered by the Pope (John XIV or XV, according to some; but more probably Sylvester II) to found a monastery near a small church dedicated to the Archangel Michael. This church had been built or rather restored a few years earlier by St. Giovanni Vincenzo, who had been bishop of a city in the Ravenna area and had retired to a hermitage on Monte Caprasio, opposite the Pirrichiano.
Even under its first abbot (Avverto), the abbey rose to considerable importance, which grew especially under the rule of Benedict I (11th century in.), Benedict II (d. 1091, founder of the abbatial school and teacher of the monk Guglielmo, the Clusian chronicler), Guglielmo I (12th century in.), Stephen (mid-12th century), and Elias (13th century, first half). It reached its peak (about 300 monks, 140 churches and priories under its jurisdiction) under Rodolfo di Montebello (d. 1359). In the second half of the 14th century, a rapid decline set in, beginning with the election of Simonica to the abbacy in 1362 and culminating in 1381 with the transfer to commendatory rule, promoted by Amadeus VI of Savoy to curb monastic corruption. The commendatory system lasted for many years during the 16th century, held by the Ferrero family, a noble family from Biella; it also passed several times to the House of Savoy, and at the request of Emmanuel Philibert, Pope Gregory XV suppressed the monastic community, assigning the abbey’s revenues to the erection of the collegiate church of Giaveno, to which the monastery was entrusted. Charles Felix chose the church’s crypt as the burial place for members of a collateral branch of the House of Savoy. In 1803, Pius VII transferred the territory to the jurisdiction of the archbishop of Turin, and finally in 1836 Gregory XVI established the Rosminians there.
Of the irregular complex, shaped by the nature of the site and the overlapping of architectural events, the church and the so-called “monks’ sepulchre,” a circular-plan Roman-era building now in ruins, are notable. The church consists of three distinct phases: the crypt, perhaps identifiable with the small church of St. Giovanni Vincenzo; the three Romanesque apses (the central one larger) resting on enormous substructures 23 m high, dating from the 12th century; and the 14th-century body in Gothic style. The access, via a staircase cut into the rock (“stairway of the dead”), is of interest for the “zodiac door,” which bears the signature of a Nicolaus, identified by some, because of certain affinities in sculptural motifs, with the author of the right portal of Piacenza Cathedral.