The Grande Museo del Duomo devotes the first two rooms of the itinerary to the exposition and the conservation of the Treasure of the Cathedral. The large central showcase hosts several liturgical objects including the Peace of Pius IV, the Milanese Pope Giovan Angelo Medici da Melegnano. The Pope donated it to his nephew and future Saint, Carlo Borromeo, Archbishop of Milan, and these to the Duomo in 1565.
It is an artifact of extraordinary beauty and preciousness. The small aedicula is supported by lapis lazuli columns with cast gold Corinthian capitals, while the base is adorned with cameos with the images of the Virgin and Saint John. In the centre is a depiction in gold of the deposition of Christ. On the sarcophagus, also in lapis lazuli, is the figure of the prophet Jonah in an episode that foreshadows the Resurrection, higher up there is a cross of thirteen faceted diamonds and a Crown consisting of an agate base and a rayed cloud and angels with ornaments of semiprecious and precious stones including three cherubs carved in garnet.
Why is it called Peace? Objects like this, tablets made of mostly in precious metals, with images of the Passion of Christ, were used to bring the peace, or the kiss of reconciliation before Communion, to the chorus and to certain persons involved in the Holy Mass. The one described here was reserved solely for kiss of the emperor or viceroy.