Church erected in the second half of the thirteenth century by the Conventual Friars Minor, who dedicated it to San Francesco, became the third cathedral in Ascoli, following an earthquake that destroyed the previous episcopal see.
The basilica has preserved the elegant late Romanesque facade tripartite with pilasters, with three portals surmounted by marble canopies and ogival lunettes, while on the sides there are two trunks of ancient columns. The Latin cross interior, with three naves and as many apses, was instead deeply modified in the late Renaissance. The vault of the central nave is decorated with frescoes of the eighteenth century. Among these is the "Nativity of the Blessed Virgin Mary" by Vito Calò.
Container of works of art of considerable value, the basilica houses the "Transit of Saint Joseph" by Corrado Giaquinto, the "Our Lady of the Rosary" by Paolo De Matteis and "Christ gives the keys to Saint Peter" by Francesco Satulli Also here is also the valuable reliquary bust of San Potito Martire.