The small land of Montalto was elevated to the rank of “city” in 1585, when its most illustrious son, Felice Peretti—born in nearby Grottammare but raised in Montalto—became pope under the name of Sixtus V. The pontiff affectionately called Montalto “our dearest homeland and cradle,” immediately enriching it with religious and civic gifts and privileges, and elevating it to the status of a diocese. A tangible sign of this concession was the sending of prestigious gifts to the new cathedral, among which was the precious Reliquary. Few works of goldsmithing can boast a history of such high profile as the Reliquary of Montalto, a relic of extraordinary value whose historical vicissitudes and changes of ownership over time produced complex morphological and stylistic transformations. In its original form, the reliquary is perhaps identifiable as an object that, between the late 14th and early 15th centuries, belonged to the French kings Charles V and Charles VI, likely the work of a Parisian goldsmith active for the royal house (possibly Jean du Vivier?).

The work reappears in the inheritance of Frederick IV of Tyrol, who died in 1439, and by 1450 it belonged to the German merchant Iachomo de Goldemont, from whom it was acquired by Leonello d’Este. In the ducal inventory, the front of the artifact (which also had a rear side depicting the “Prayer in the Garden”) is described as it appears today: a gilded silver plate with a large angel with outstretched wings supporting the dead Christ, flanked by two kneeling angels holding a lance and a column; in the two roundels along the frame are depicted the Crucifixion and the Flagellation; above, three pairs of angels surround God the Father, appearing in the gable flanked by two angels holding scrolls with fragments of the Creed; below, between two quadrangular compartments containing relics, the Deposition completes the Passion cycle. The figures are made in en ronde bosse enamel (opaque or translucent applied over gold relief), with a refined chromatic richness enhanced by a profusion of gems (sapphires and spinels) and pearls.

By 1457, the reliquary appears in the inventory of Venetian cardinal Pietro Barbo, later Pope Paul II (1464–1471), perhaps given to him by Borso d’Este. It was the cardinal who inserted the original into its current gilded silver mount, decorated on the reverse with large vegetative scrolls of classical taste, probably made by a Roman goldsmith, and adorned four times with the cardinal’s coat of arms. At the top, a small shrine was added containing a Byzantine sardonyx cameo depicting Jesus Christ. Of the two dedicatory inscriptions along the base, the rear one, dating to the 15th century, commemorates Pietro Barbo, while the front one was added by Pope Sixtus V (1585–1590), who in 1587 took the precious object from the Vatican Treasury to offer it to the town of Montalto delle Marche, his “dearest homeland,” after entrusting it to the goldsmith Diomede Vanni for restoration and to modify the Barbo coats of arms, adding the heraldic symbols of the Sistine family.