The objects that make up the Treasury of the St. Lorenzo Cathedral are very heterogeneous in origin and cover a time span of almost two millennia, however they are largely homogeneous in the sense of being (generally) functional to the act of worship. Within this small but extraordinary heritage, a sort of common thread can be traced through the works concerning San Giovanni Battista (John the Baptist) - Jesus’s cousin who preceded his preaching and, is therefore, also called the Precursor – these objects document the centuries-old devotion paid to him in Genoa even before his official proclamation as patron saint of the city in 1327.
As the Gospel of St. Mark reports, for having censored the dissolute conduct of King Herod, John the Baptist was imprisoned and subsequently - at the instigation of Herod’s wife Herodias - beheaded: at which point, as proof of the execution, his severed head was shown to the couple placed on a salver. This very object, exhibited in the second of the three rooms that open onto the central space of the museum, constitutes the first stop on this itinerary: the plate in question is a rare and precious Roman artefact in chalcedony, dating to the first century AD, which because of the color of its veining, especially when illuminated from the back, seems stained with blood. The tradition that it was used to present the saint's head was further strengthened in the fifteenth century when the dish, at that time in France rather than Genoa, broke and to remedy, or conceal, the damage a gold frame was fitted, in the center of the frame was located an enamelled representation of the saint's severed head, the Parisian goldsmith who undertook the work is unknown but was clearly very highly skilled.
After his martyrdom, the saint's body was cremated and the Genoese came into possession of his ashes during the First Crusade when in 1098 , led by Guglielmo Embriaco, they landed at Mira (or Myra), in what is now Southern Turkey, where the remains of San Nicola were also preserved. According to sources, the ashes were initially divided among the various ships participating in the expedition, but a storm prevented the boats from leaving until the sacred remains were gathered onto a single vessel and so they arrived triumphantly in Genoa.
In order to adequately preserve and honor the ashes, a first ark was made during the 12th century which, according to a late 17th century tradition, was a devotional offering from the Emperor Frederick Barbarossa. This chest shaped container covered with silver depicts, in relief, scenes from John the Baptist’s martyrdom, is visible in the same room as the plate and close to it.
Shortly after, around 1225, a new ark was prepared, this time in marble, its role was to store the relics inside the cathedral and, for this reason, is located inside the chapel dedicated to John the Baptist on the left aisle of the cathedral itself. It is the work of one of the French sculptors who were at that time working on the portals of the church.
Starting from 1327, recalling the miraculous departure of the ashes from Mira, people began to attribute to the relics the power to protect ships and sailors, so that from that date the saint was proclaimed patron saint of Genoa and his relics carried in procession on his feast day (24 June): during the rite the archbishop would take the reliquary that normally contained his ashes and blesses the sea invoking the protection of God on sailors, their ships and on the goods they carry.
This tradition, over time, created the need for a suitable object, a precious processional chest, in which to place the relics for their transport through the city streets. This chest was commissioned by the Priors of the Chapel and was created between 1438 and 1445 mainly by Teramo Danieli, to whom the overall design is attributed, and Simone Caldera. The extraordinary product of their work is a sort of miniature cathedral, surmounted by densely decorated spires and pinnacles. It sits on display in the same area in which the plate and the ark of Barbarossa are exhibited. Along the sides of the chest, within flowering shrines, the entire life of the Baptist is illustrated: from the announcement of his birth to his father Zaccaria, to the burial of his remains after his martyrdom.
In the same room is exhibited, in the display case that contains the plate and the ark of Barbarossa, an object which testifies to the fact that devotion to the saint could also assume less public dimensions, one in which only the city authorities were involved on very particular occasions or prelates or visiting sovereigns, it is for this reason that an unknown Genoese silversmith in 1576 was tasked with preparing a box in gilded silver to permit a ritual kissing of the, much venerated, relics.
The final item on this itinerary is exhibited, due to its size, in the display case located in the first room that opens onto the central space of the museum: it is a splendid cabinet - the product of the Florentine grand-ducal workshops, dating from towards the end of the sixteenth century, initially, as is indicated by its enamel and pearl decoration, it would have had a non religious scope: a precious container for some equally or perhaps even more precious object. In some way it came into the possession of a Genoese family, the Pincetis, and was subsequently sold by them to the cathedral where it was used to house the ashes of San Giovanni Battista when they were put on public display. During the seventeenth century the cabinet was surmounted by a silver figurine of the Saint - which explains the hole in the center of the rock crystal situated above the cover of the cabinet – it was removed and placed in the baptistery following a break of which the outcome is clearly visible.