The cathedral basilica of the Virgin of the Assumption, commonly known as the cathedral, is the main place of Catholic worship in the city of Lodi, in Lombardy, the episcopal seat of the diocese of the same name.
It is one of the largest churches in Lombardy and the oldest monument in Lodi: the first stone of the building, in fact, was symbolically placed on 3 August 1158, the same day the city was founded.
In March 1970 Pope Paul VI elevated it to the dignity of a minor basilica.
In Romanesque style, it is one of the largest churches in the whole of Lombardy. The first phase of its construction, for which many materials from the buildings of ancient Laus Pompeia were probably used, dates back to the period between 1158 and 1163; in fact, the crypt was solemnly inaugurated with the translation of the relics of San Bassiano on 4 November 1163, in the presence of Emperor Frederick Barbarossa. A second phase dates back to between 1170 and 1180, but the façade was completed only in 1284. The church replaced the ancient church of Santa Maria di Lodi Vecchio in its cathedral functions.
At the beginning of the 16th century the apostolic administrator of the diocese, Claudius of Seyssel, promoted restoration and modernization works. The most visible sign was the opening of the two mullioned windows on the facade and the construction of the new rose window. Subsequently, the eighteenth-century restorations - carried out by the architect Francesco Croce - altered the original appearance of the building, which was however restored in the years 1958-1965.
The church is recognized as an Italian national monument.