Il Duomo, Florence, Tuscany Region, Italy. The Basilica di Santa Maria del Fiore (English: Basilica of Saint Mary of the Flower) is the main church of Florence, Italy. The cathedral is the mother church of the Roman Catholic Archdiocese of Florence. The church is particularly notable for its 44 stained glass windows, the largest undertaking of this kind in Italy in the 14th and 15th century.