The complex of St. Antonio al Monte was erected in 1474 on the hill of St. Biagio. It was then entrusted to the Observant Franciscans that, thanks to the work of Fra Bernardino da Feltre, succeeded in establishing a Mount of Piety in Rieti.

The convent has been designed following the simple and austere style typical of the Orders of Friars Minor. The adjacent church saw a significant transformation at the end of the 17th century thanks to the work of the architect Michele Chiesa.

The building, with a single nave, has three chapels on each side. On the left, the chapel frescoed by Vincenzo Manenti in 1652. On the right, the one dedicated to the Immaculate Conception, with stucco decorations inspired by the famous Antonio Gherardi, born in Rieti and very popular in Rome as an
architect, scenographer and painter since 1670.

The altarpiece dating from around 1697 was certainly produced by his own hand. The Immaculate is organized like a typical Baroque “machine” that sees the Virgin on the top which, with the usual colors of red, allusion to the martyrdom of Christ, and blue, allusion to her epithet of Queen of Heaven, stands on the white crescent, attribute of chastity. Four festive angels,
two at the bottom and two at the top, encircle her with the crown of twelve stars. The architectural and naturalistic context creates a circular dynamic movement animated by fluctuating flashes of light, very close to those works by Gherardi visible in Rome and Gubbio. The painter, in the season of the renewed Roman classicism of Carlo Maratta, does not renounce to the reckless fluid baroque experimentations of the youthful years, denoting an uncommon late 17th century expressive autonomy.