It is the cathedral church of the Roman Catholic Archdiocese of Palermo. The church was built in 1185 by Walter Ophamil, the Anglo-Norman Archbishop of Palermo. The church is characterized by a unique architecture that resulted from the many modifications and restorations that the church went through, the last of which was in the eighteenth century. Where the current classical appearance of the church, represented by inscriptions, decorations, and decorated domes, dates back to the restoration work that took place during the period between 1781-1801 AD. There are also certain parts of the church and some architectural elements that date back to the medieval period, while the south balcony was added in the early Renaissance.