Milan Cathedral between the Holy Nail, the meridian and symbols

Milan Cathedral is the very symbol of the city, but its postcard image hides a wealth of meanings that escapes anyone who merely admires its spires. Built over more than five centuries, it is a book in stone in which medieval devotion, Enlightenment science and popular traditions live side by side. Reading it carefully means discovering relics, astronomical instruments and a population of statues that few visitors truly look at.

A building site lasting five centuries

Work began in 1386, under the lordship of Gian Galeazzo Visconti, who wanted for Milan a cathedral able to rival the great Gothic churches north of the Alps. To manage the site the Veneranda Fabbrica del Duomo was created, an institution that still exists today. The marble came from the quarries of Candoglia, near Lake Maggiore, and reached the city along the Ticino and the Navigli canals.

A widespread popular tradition holds that the blocks destined for the site bore the initials AUF, ad usum fabricae, which exempted them from duties. From this would come the Milanese expression «a ufo», meaning for free. The etymology is fascinating but debated, and should be presented as a hypothesis. The façade was completed only in the nineteenth century, at Napoleon's wish, and some details were finished as late as the twentieth.

The Holy Nail and the rite of the Nivola

Above the high altar, at a great height, is kept a nail that tradition identifies as one of those of the Crucifixion. According to the devotional account it was found by Saint Helena, mother of Constantine, and reached Milan in ancient times. Once a year, around 14 September, the feast of the Exaltation of the Cross, the archbishop rises to the relic aboard a cloud-shaped lift, the Nivola.

The rite gained importance with Saint Charles Borromeo, who during the plague of 1576 carried the nail in procession through the streets. Popular belief even attributes the first mechanism of the Nivola to Leonardo da Vinci, who worked in Milan at the Sforza court, but there is no documentary evidence of this authorship.

The meridian and the people of statues

Entering by the main door one notices on the floor a long brass strip crossing the nave: it is the meridian line made in 1786 by the astronomers of the Brera Observatory. A small hole in the vault lets through a ray of sunlight which, at solar noon, falls on the line, indicating the day of the year thanks to the zodiac signs engraved along its length. It was used to regulate the city's clocks.

Thousands of statues keep watch over the cathedral, among them saints, prophets, allegorical figures and monstrous gargoyles. The fantastic creatures of the gargoyles had a practical function, draining rainwater, but also a symbolic one: they represented the forces of evil kept outside the sacred space. On the highest spire the gilded Madonnina has shone since 1774, having become the city's beloved protector.

Milan Cathedral is therefore much more than a masterpiece of Gothic architecture. It is a place where the relic of the Passion, the astronomical instrument and the stone bestiary tell three different ways of thinking about the relationship between humanity and the sacred. Knowing these stories, while distinguishing documented facts from traditions, turns a visit into an exploration of the city's symbols.