The foundation of the church should date back to long before 1178 (the year of the first attestation that has come down to us), since the dedication to San Michele reveals Lombard origins. As early as the 5th century there was probably already a church dedicated to the saint in Potenza; a 5th-century mosaic, in fact, found under the floor of the current church of San Michele, reveals its belonging to a late Roman structure reused on the occasion of the foundation of the first basilica. The main portal has a double jamb with a double round arch. A horizontal element between the central pilasters underlines the setback of the central nave masonry. The slopes of the minor naves and the major sides of the central nave and the right lateral one are lightened by a row of hanging arches. The side entrance to the church opens in the center of the right wall, grafted onto a thickening element of the masonry. The portal is in stone with exposed worked ashlars and has, above the lintel, in the lunette, a bas-relief of 'Madonna and Child' which presents, on the left, the Franciscan symbol, and on the right, a decorative element with floral motifs. The interior of the church is of the basilica type, with three naves and three apses, the central nave is higher than the side ones.