The Cathedral of Santa Maria Assunta Oristano, is the Cathedral of the city and the mother church of the Arborense Archdiocese. It is located in the historic city centre, in Piazza Duomo.
In April 1957 Pope Pius XII elevated its as a minor basilica.

The Oristano Cathedral stands on the site of a Byzantine era settlement, as evidenced by the 7th century burials found in the square in front of the building. The existence of the cathedral, the ecclesia “sanctae Mariae de Orestano”, is documented since 1131; The sixteen columns kept in the courtyard of the cathedral and the capitals kept in the nearby seminary make it possible to assume that the primitive Romanesque building had three naves.

Some restorations, commissioned by Archbishop Torgotorio de Muru, were carried out in 1228, when Master Placentinus signed his signature on the bronze doors of the wooden door, currently kept in the chapter hall. By 1348, the transept was built with the four Italian Gothic chapels.

The grave deterioration of the Cathedral of Oristano in the first half of the 18th century caused the reconstruction work that led to the present building, saving little of the ancient Romanesque-Gothic factory. The works, commissioned by Archbishop Antonio Nin and the chapter, began in 1729.

They were initially entrusted to the Cagliari architect Salvatore Garrucciu and later, after the death of the latter, to Giovanni Battista Ariety of Alghero. The temple was consecrated in 1745 but the works ended only during the second half of the century. Between 1830 and 1837 the semi-circular chaplains of the transept were constructed according to the design of the Piemontese architect Giuseppe Cominotti, commissioned by Archbishop Giovanni Maria Bua, while in 1912 the paintings decorating the interior walls of the cathedral date back to 1912.

Archbishop Ignazio Sanna decides to complete the liturgical adjustment work with the placement of the new canteen and the new white and red marble of Michelangelo type after nine years of decision in the end of 2015. The dedication took place on January 10, 2016 with the concelebrating presided by the archbishop concelebrated by some Sardinian bishops and the Arboretum presbytery. During the rite the relics of St. Archelao and Holy Right are located.

The Cathedral of Oristano overlooks the large square with its main, incomplete view in cantons of trachite in sight, and on the north side, moved by the semicircular apse of the arm of the transept and flanked by the beautiful bell tower with octagonal cane, Medieval origins and completed in the eighteenth century by the majolica-coated onion cupola.

The interior, with a Latin cross plan, consists of a single, wide nave, with three chapels on each side, transept and quadrangular apse. The crossing of the nave with the transept is covered by the octagonal dome, with a drum set on four plumes in which the Evangelists are painted. The interior of the temple is adorned with numerous works of art, including the 14th-century wooden statue of the Annunziata, attributed to Nino Pisano, housed in the first chapel on the right and the eighteenth-century altar of the sculptor Pietro Pozzo, In the Baroque style, in the chapel dedicated to St.Archelao, patron saint of Oristano.

The presbytery, on the model of the cathedral of Cagliari and the Cathedral of Sassari, is raised, closed by a marble balustrade and two lions of the same material placed at the base of the access staircase. The main altar and the sideboard, in marble, are the work of Pietro Pozzo. Behind the altar there is the precious wooden chapel, eighteenth century, while on the back wall of the apse is placed the large round cloth, where the Assumption is depicted, with a gorgeous golden frame straight from the angels. On the side walls are instead placed two large rectangular canvases of the Marghinotti, depicting the Adoration of the Magi and the Last Supper, the latter theme taken over in various works by the nineteenth-century artist.

In the transept are the Gothic surviving Gothic chapels dating back to the 13th century, including the Chapel of the Madonna del Rimedio, with a cruise liner, a gothic bifora open at the bottom and an altar adorned with the remains of a carved marble pluteo dating from the 9th century. Always in the transept, the nineteenth century chapels, in neo-classical style, are dedicated to Saint Luigi Gonzaga (north arm) and to St. John Nepomuceno (south arm), decorated with sculptures by Andrea Galassi.

From the sacristy of the Beneficiaries it is possible to access the so-called “Archivietto”, a small rectangular, sixth-century square chapel, which is stylistically an interesting combination of late-19th-century architecture and elements of Renaissance classicism. The “Archives” was erected to extend the apse, which was separated during the eighteenth-century restorations with the erection of a wall, thus becoming a self-contained archive.

Pipe organ
The pipe organ of the Cathedral of Oristano, located in the right arm of the transept, was built in 1960 by the company Tamburini; Originally located behind the main altar, in 1970, the same firm was divided into two bodies, widened and moved to the current accommodation.

Currently the Grand’Organo (first keyboard) and the Pedal are located near the right wall of the right transept, the Espressivo (second keyboard) is instead placed in a small chorus at the right of the apse, with an exhibition of canes mute.

The console, located below the stairway to the pulpit between the nave and the right transept, has two keyboards of 61 keys each and a concave-radial pedal of 32 notes. The transmission is electropneumatic.

    

Here the map to the Cathedral of Santa Maria Assunta Oristano: