When was the Milan Cathedral built?
Construction of the Duomo di Milano began in 1386 and its final details were completed in 1965 — the cathedral took nearly six centuries to complete. The endpoint is unusually precise: the last of the five bronze portals was inaugurated on 6 January 1965.
So when someone asks “when was it built,” the honest answer is a range, not a date. The building you see is medieval in plan, largely 19th-century in its facade, and 20th-century in its final doors.
Who founded the Duomo, and why?
Construction began under Archbishop Antonio da Saluzzo, with the political and financial backing of Milan’s ruler Gian Galeazzo Visconti. A year in, the project got the institution that still runs it today: the Veneranda Fabbrica del Duomo, established in 1387 by Gian Galeazzo Visconti — it has been safeguarding and restoring the Duomo for more than 630 years.
Visconti made a second decision that defined the building. Instead of Lombard brick, the cathedral would be faced in marble — and on 24 October 1387 he ceded the Candoglia quarry on Lake Maggiore’s watershed to the Fabbrica. Marble blocks travelled to Milan by water — down the Toce, across Lake Maggiore, along the Ticino and the Naviglio Grande — a supply route that stayed in use until 1920.
How did construction actually progress?
Slowly, and with a rotating cast of chief engineers — Simone da Orsenigo in 1387, then French masters Nicolas de Bonaventure in 1389 and Jean Mignot in 1399, brought in to keep the Gothic engineering honest. The high altar was consecrated by Pope Martin V on 16 October 1418, while the building around it was still a construction site.
The Renaissance and Baroque centuries kept adding hands: Giovanni Antonio Amadeo from 1486, Pellegrino Pellegrini from 1567. The crown came late: the Main Spire went up between 1765 and 1770, and the gilded Madonnina — 4.16 metres of gold-covered copper — was finally raised onto it in the last days of December 1774. At that point the Duomo had its silhouette — but still no finished facade.
The interior kept changing too. Much of the stained glass you see today is not medieval: new windows replaced old ones between 1829 and 1858, though panels by fifteenth-century masters like Cristoforo de’ Mottis and Niccolò da Varallo survive from the 1470s. Even the organ is a latecomer — built in 1938 by Mascioni and Tamburini, and now the largest instrument in Italy.
What did Napoleon do for the Duomo?
He ended four centuries of procrastination: on 20 May 1805, about to be crowned King of Italy, Napoleon ordered the facade to be finished. The main facade campaign ran 1807–1813, and in thanksgiving a statue of Napoleon was placed at the top of one of the spires — he’s still up there among the saints.
It’s a good story to carry onto the rooftop: much of the spire-and-statue skyline you walk through on the terraces is 19th-century work finishing a 14th-century design.
When was the Duomo actually finished?
In 1965 — the final stretch of work ran from 1909 to 1965, closing with that last bronze portal in January 1965. “Finished” deserves quotation marks, though: restoration never stops.
By then, six centuries of carving had put over 3,400 statues on the building, carried on 135 spires — a workload that explains, better than any single date, why the project outlived twenty generations of its builders.
The Veneranda Fabbrica still runs the maintenance, still employs its own craftsmen, and still operates the Candoglia quarry so that replacement marble matches the original stone. Its music chapel has been active continuously since 1402. The Madonnina herself was last re-gilded in 2012. Scaffolding somewhere on the building is effectively permanent — reviewers mention it constantly — and it’s the price of a 600-year-old marble building staying standing.
If the history is what draws you, the archaeological area under the cathedral — with a baptistery dating to 335 — takes the timeline back a thousand years before the first stone of the current building; we cover it in what’s inside the Duomo. And if you’re planning to see it in person, you can compare Duomo tickets — the full pass includes the archaeological area and museum.