The abbey was built around 996 over the previous cathedral, which has existed since the seventh century. The first abbot was Pietro Vincioli, a noble from Perugia, later canonized. In the following centuries the abbey increased enormously his power, until in 1398 it was burn from the citizens, accusing Abbot Francesco Guidalotti to have taken part in the conspiracy against Biordo Michelotti, chief of the popular faction of Raspanti. The monastery had a new period of expansion under Pope Eugene IV, who joined the Congregation of St. Justina of Padua, keep making it a position of prestige and power in the city. The abbey was temporarily suppressed by the French in 1799. The monks encouraged the revolt of Perugia in 1859 against the Papal State, and so after the Unification of Italy, the new government allowed them to remain in the abbey. Shortly before arriving at the monastery you pass through a door made in the fifteenth century, designed by Agostino di Duccio. The gate leads into a monumental façade with three arches, designed in 1614 by architect Valentino Martelli. The entrance of the church is on the left side of the cloister. Portions of the original façade of the basilica can be seen on the right and left of the fifteenth-century portal, with an arcade that includes some of the frescoes of the fourteenth and fifteenth century. The polygonal tower, to the right of the portal was rebuilt in 1463-68 at the Florentine Gothic style, based on a design by Bernardo Rossellino.