The display presently located in the Chapel of St Pius V is probably the most important of tho- se which preserves the Christian part of the collections of the Decorative Arts Department. It contains the splendid shrines that were found on June 6, 1905 in a cypress box that, for want of Pope Leo III (795-816), was placed under the altar in the papal oratory of St. Lawrence. In the past, this chapel was part of the southern perimeter of the complex attached to the Constantinian Basilica of St. John Lateran (the famous Lateran Patriarchate, headquarters of the public offices of the papal court throughout the Middle Ages) and survived later as part of the renovated Palace and Holy Steps complex, built under Sixtus V in 1586. Throughout the early Middle Ages until the late thirteenth century, the ‘Treasury’ was increased by the addition of new objects inside the case. The continuous influx of relics from the East, necessitated the construction of new shrines for their conservation or the adaptation of the older ones for their display. In addition to the religious veneration of multitudes of the faithful (which earned the location of the ‘Treasury’ the biblical nickname of Sancta Sanctorum, by which today it is universally known) the reliquaries collected under the altar were the subject of accurate inventories by Lateran clerics, the most recent of which, refers to the concluding session of the Fifth Lateran Council (1512-1517) and attests to a formal recognition of the pieces even under Leo X. From that date, and for almost four hundred years, the altar and its precious content remained sealed and virtually unexplored, until their final unveiling early last century, at the inquiries mentioned above. Without mentioning the importance of many of these shrines – and relics that they once contained – for the history of the Western Christianity, it will be sufficient to draw attention to the value and the beauty of some of them, such as the enameled cross of Paschal I, the embossed silver containers donated to the ‘Treasury’ by that same Pope, the reliquaries of the “head of Santa Praxedes”, the “True Cross”, or “stones of the Holy Land”, respectively from the XI, X, and V centuries, to understand the centrality of these artifacts in the exhibition itinerary of the Museum. Unfortunately, the outdated structure of the display – dating, in its original construction, to 1964 – is no longer in line with modern exhibition standards regarding storage, lighting, and arrangement.