Milan Cathedral was begun in 1386 on a site long occupied by the city’s principal Christian churches. Archbishop Antonio da Saluzzo and Gian Galeazzo Visconti, lord and later duke of Milan, supported a new cathedral that would proclaim both religious devotion and dynastic ambition. In 1387, the Veneranda Fabbrica del Duomo was established to direct construction, raise funds, obtain materials, and coordinate workers. That institution has continued to care for the building, making the cathedral’s history inseparable from the organization created to build it.

The project adopted a northern Gothic language unusual in Italy. Architects, engineers, sculptors, and stonecutters arrived from across Europe, bringing competing ideas about vaults, proportions, buttresses, and decoration. Visconti granted access to the Candoglia marble quarries near Lake Maggiore and allowed stone to travel duty-free along waterways into Milan. The pale marble became the cathedral’s defining material. Construction advanced unevenly around the apse, transepts, nave, and roof as technical disputes, political change, limited funds, and the sheer scale of the design repeatedly altered schedules and plans.

By the sixteenth century, Archbishop Carlo Borromeo sought to make the still-incomplete building conform more closely to Counter-Reformation worship and Roman architectural taste. Pellegrino Tibaldi redesigned parts of the presbytery and proposed a classical facade, while later architects returned to more emphatically Gothic solutions. The cathedral accumulated stained glass, tombs, altars, sculpture, organs, and the celebrated statue of Saint Bartholomew Flayed. Above, a forest of pinnacles and statues developed over generations. The gilded copper Madonnina was placed on the main spire in 1774 and became an emblem of Milan.

The western front remained unresolved until the Napoleonic period. Preparing for his 1805 coronation as king of Italy in the cathedral, Napoleon ordered the facade brought toward completion, and work proceeded rapidly under designs that combined earlier schemes. Construction and decoration nevertheless continued through the nineteenth and twentieth centuries. The final bronze doors were installed in the modern era, and the building’s completion is often dated to 1965, nearly six centuries after work began. That long chronology explains why apparently unified Gothic forms contain the decisions of many different periods.

The Duomo remains the cathedral of the Archdiocese of Milan and an active setting for liturgy as well as a major visitor site. Its roof terraces allow close views of the buttresses, pinnacles, sculpture, and changing city around them. Candoglia marble is beautiful but porous, so pollution, moisture, temperature shifts, and structural movement require constant inspection and replacement of damaged blocks. The Veneranda Fabbrica still manages quarrying, conservation, workshops, archives, and access. Milan Cathedral is therefore not a finished medieval relic but an extraordinary continuing building project sustained by six centuries of civic labor and religious use.