Since then it took the name of “Church of St. Gregorio” or “Collegiate”.
In 1661 it was restored by the canon Giovanni Pazzaglia and assumed its present form.
The building, with a Latin cross plan, has a single aisle and an extraordinary wooden ceiling. Its interior hosts the “Nuns’ Chapel”, so called because of the adjacent convent of the Clares. They preserve the Holy Thorn (donated to the population of Montone by Carlo, son of Braccio Fortebracci and displayed to the public only on Easter Monday and on the penultimate Sunday of August of each year). The church is rich with frescoes and canvasses, such as The Last Supper, an artwork above the sacristy door by the Flemish Calvaert. The vault fresco was painted by Giovanni Parenti, leader of the Florentine Academy. It dates to the first half of the 1700s and represents the apostles waiting for the descent of the Holy Spirit.