Towards the end of the 19th century, Piacenza Cathedral was showing signs of collapse and therefore the bishop with the open letter ‘Pel nostro duomo’ (February 9^th, 1894) announced the start of restoration work, for religious, aesthetic, moral and social reasons, in a context where the labour crisis had hit hard.

The bishop was president of the Commission that guided the building site according to 19th-century positivist and Viollet-Leduchian canons. The Technical Management, appointed in March 1894, consisted of engineers Giuseppe Manfredi (later retired) and Guglielmo Della Cella (died 1896) and architect Camillo Guidotti. Beginning in 1898 with the restoration of the façade, the building site was extended to the entire structure and was completed in June 1901, leading to the ‘liberation’ of the façades with the elimination of the leaning bodies and the overall consolidation.

Guidotti, looking at the technical innovations of the time, outlined the method in his “Studies and Proposals” for the Cathedral (1895): … when there is the old type to be reproduced or imitated, remaking ashlars or parts that have been destroyed or not completed… it will be best if the new parts are left in their natural colour, and it will be best to distinguish them with certain signs, so that posterity will not be misled. Those additions or alterations that have been made to the building may be conserved… as long as they do not manifestly disfigure or disguise notable parts of the monument, in which case they must be removed or destroyed.

On the façade, the rose window was consolidated by replacing the central lintel, the median side and upper galleries were restored with the exchange of small columns, bases and capitals, and the gable roof slabs were repaired. The clock face was removed and the corroded sandstone covering slabs were changed. The central porch was remodelled, eliminating the renovations carried out since the 15th century. The loggia was lowered, the Baroque balustrade demolished, the wooden statue of Abundance removed (it is in the bishop’s palace), the lower columns modified and the capitals replaced with new ones of the Evangelists, the work of Pier Enrico Astorri, like the panels on the front of the prothyrum with Faith, Hope and Charity.

For the sculptural restoration, Guidotti carried out surveys of materials to use similar ones, inserted copies when it was impossible to weld detached pieces, completed partially damaged artefacts on an analogical basis, inserted plugs into original elements, created fictional works in the absence of original testimonies, such as for the front of the crypt and pulpit. The artefacts designed by Guidotti were executed by Fedele Toscani, Giovanni Pagani, Pier Enrico Astorri, Annibale Monti and the stonemason Pietro Spelta.

An architrave by Astorri based on a design by Guidotti with the Miracles of Christ was inserted in the central portal. The 14th-century fresco in the lunette was destroyed and replaced with the Madonna assumed between Saints Antonino and Giustina (1900) by Eugenio Cisterna.  Sculptures by Antonio Marina (Immaculate Madonna and Seated Prophet) were added to the right buttress on the front and south flank of the Cathedral, surmounted by a canopy. On the north side, after demolishing the Loggia della Cancelleria, the loggias were rebuilt, except for the first one on the counter-façade; statues of Giovanni Battista Scalabrini, Carolippo Guerra and Camillo Guidotti (Monti company, 1901) were placed in place of three small columns.

The portal on Via Guastafredda, modified in 1720 to create a connection to the bishop’s palace, was restored by replacing the original stylised lions with others purchased from the antiquarian Rambaldi of Bologna (1902).  In the apses, the central window was restored by making replacements and adding two lateral masks.

Inside the cathedral, the first four vaults of the nave and some of the minor ones were rebuilt, the ancient stairs to the attics, triforiums and women’s galleries were reopened, and the crypt was set back according to its original size and provided with a front designed by Guidotti.

The altars and altarpieces were removed, the stuccoes and frescoes by Ludovico Carracci and Camillo Procaccini were removed from the sanctuary using the “strappo” technique by the Steffanoni brothers from Bergamo, and the latter were housed in the bishop’s palace in an attempt to restore the medieval appearance.  The frescoes by Marc’Antonio Franceschini, removed from the prelude to the dome gallery, were largely lost.

During the building site, medieval wall paintings were rediscovered (St. Christopher, St. George, St. Antoninus in the left arm of the transept and the Stories from the Life of St. Martin and St. Alexis in the side chapels of the presbytery, to which Luigi Morgari added images).

Medieval mural paintings were commissioned from Eugenio Cisterna: in 1903, he depicted the bishop saints from Piacenza in the left apsidiole of the corresponding transept and decorated the central apse with the Madonna del Popolo. Alfredo Tansini decorated the right apsidiole with the Holy Family (1901). The neo-medieval altar, based on a design by Guidotti, was made by Toscani, as was the altar in the right transept. Cisterna, to whom the Good Shepherd above the door to the bishopric also refers, is also responsible for the ornamentation of the apsidioles and central chapel of the right transept with female Saints and male Saints linked to the Blessed Sacrament and the Triumph of the Eucharist in the vault (1901).

Some sketches at the Scalabrinians’ mother house are preliminary proposals by these well-known decorators of the time. In the presbytery, after demolishing the 17th century extension and identifying the original perimeter, Guidotti designed the restoration in accordance with his vision of the Middle Ages. Fedele Toscani prepared the ambo and marble pulpit.

Later, the organ by Giovanni Tamburini da Crema with some pipes by Serassi (1818) was installed. Giovanni Vecchia, the author of the neo-Gothic confessionals, modified the wooden choir by Giovanni Giacomo Genovesi (1466) and put his hand to parts of the polyptych by Antonio Burlengo and Bartolomeo da Groppallo (1443-1447), moved into the sanctuary from the counter façade.