At the beginning of the 12th century, the young hermit Guglielmo, en route to the Holy Land after pilgrimages to Santiago de Compostela and Rome, stopped in Irpinia following the Appian Way. There, starting from 1133, he founded first the Abbey of Montevergine and then the monastic settlement of the Most Holy Saviour here at Goleto.

To build the latter, Guglielmo received a large tract of land as a gift from Ruggero, the Norman lord of nearby Monticchio.
The complex was largely constructed using spolia from a pre-existing Roman settlement that had belonged to Marcus Paccius Marcellus.

Flanking the original church, an innovative ‘double monastery’ was built, featuring two wings and two cloisters, the larger of which was designated for the nuns. Within this religious community, supreme authority rested with the abbess, while the monks were responsible for liturgical service and manual labour.

Guglielmo never reached the Holy Land! He died in Irpinia, here at Goleto, on 24 June 1142.
Eight hundred years after his death, in 1942, Pope Pius XII proclaimed him the Primary Patron of Irpinia.