In the Museo del Duomo di Milano, within the Lombardy Renaissance room, immediately after the rooms dedicated to the Visconti era, walking among the labyrinth of statues and marble, one can see, down low, almost at the end of the room, three perforated bas-reliefs panels measuring 0.72 square meters each.
These are the “formelle a traforo gotico” [Gothic tracery panels] with Ducal crests and devices, carved by Veneranda Fabbrica workers in the third quarter of the 15th century.
Due to various unusual incidents regarding preservation of pieces within the museum, the marble panels were not easy to place. Ugo Nebbia, head of displays in the New Museo del Duomo (inaugurated on 28 November 1953), came up with the theory that "the panels with Visconti-Sforza crests and devices, were probably the remains of an altar or sepulchre demolished during the time of Saint Charles." Rossana Bossaglia, who oversaw the first indexing of the Museo del Duomo's scientific catalogue in 1978, classified the pieces as "transennae" of uncertain origin without specifying their method of use.
Due to their small size, their use as balustrades to demarcate sacred or liturgical spaces was excluded. Furthermore, the fact that their rear sides are not carved implies that they were only visible from the front, perhaps mounted within an architectural element like a wall or window. Regardless, their original position within the Duomo remains to be determined. It is possible that the panels were removed due to their heraldic nature under Archbishop Charles Borromeo.
The first of the three crests, known as “a freno” or “moraglia”, was adopted by Gian Galeazzo Visconti to embody several of the qualities that he was known for: moderation, temperance, and self-control. The bridle is a symbol of jurisprudence and represents the careful thought which moderates judgement and the application of the law, and is furthermore accompanied by the motto “ich verghes nit”, or rather "I do not forget", added by Galeazzo Maria Sforza at the moment of his succession.
It is the insignia of Visconti power.
The second emblem is employed multiple times by the Visconti family, following the appointment to Imperial Vicar (1294) of Matteo I Visconti, who was permitted to incorporate the Imperial Eagle into the Visconti coat of arms and, later, the viper swallowing the Saracen. This became the "Ducal" emblem.
At the centre of the third bas-relief's lobe, the image of the dog sitting under a pine tree is depicted, traditionally ascribed to Bernabò Visconti, lord of Milan during the middle of the 14th century, a lover of hunting and owner of more than 5000 dogs. A heavenly hand emerging from the clouds, accompanies the dog (a greyhound) sitting under the pine tree. At times the hand restrains, at others it frees from the leash, as in this case. The image is associated with the motto “QUIETUM NEMO IMPUNE LACESSET”, or rather “no one provokes the peaceful with impunity”, which in other words means that he who possesses this emblem will be ready to retaliate under the protection of heaven in the event that he is attacked for no reason.
These and many other unique items can be seen in the Museo del Duomo's new catalogue: “Milano – Museo e Tesoro del Duomo”, [Milan – The Duomo's Museum and Treasure] published in June 2017 and available at the Duomo Shop.