**2. Historical Context of Ecclesiastical Heritage and Collecting within the Catholic Church**

The recognition of Christianity as religio licita by the Edict of Milan in 313 allowed the public and triumphant exteriorisation of the cult (Drake 2012). Emperor Constantine initiated a vast programme of temple construction in Rome and the Holy Land, providing them with dignified furnishings, such as chalices and patens in precious metals and rich altar adornments. At the same time, Saint Helena, Constantine's mother, converted to Christianity and began a pilgrimage to the holy places in Palestine, where tradition attributes the inventio (Jensen 2017), or discovery, of the site of the crucifixion, whose relics she brought back to Rome. Religious relics of saints and martyrs constitute the starting point for the constitution of medieval ecclesiastical treasures whose dominant value is of a spiritual order, such as thesaurus gratiarum. However, allied to this was the patrimonial and artistic value of the reliquaries and the church's set of tools and vestments, constituting a treasure in a literal sense (Cordez 2005, p. 57), which contributed to consolidating the concept of interdiction. Brief apparitions, either in liturgical use or in a sporadic presentation to the admiration and veneration of the faithful, contribute to underlining the intrinsic condition of the separation due to the sacred things. The ecclesiastical treasures fulfilled inventory, reserve, preservation, and exhibition tasks that, as we say today, are inherent to museological activities. They are, therefore, not only an obligatory reference in the proto-history of museology but also the historical background of ecclesiastical museums.

During the Renaissance, the classical influence, conveyed by the humanist current, stimulated the taste for collecting genuine works or replicas from antiquity, paintings, sculptures, and exotic materials in the cabinets of curiosities. In the Capitol of Rome, Pope Sixtus IV founded the Antiquarium with a precious collection of ancient sculptures

that he offered to the city's people (Jacks 1993). Pope Julius II exhibited his collection of classical art at the Vatican (Piana 2020). Papal collecting stimulated the development of other ecclesiastical collections that functioned as a sign of dignity and prestige and a privileged instrument in searching for knowledge. However, these artistic collections are not distinguished from the royal or aristocratic collections of the time, where, except for iconography, there are no objects of a religious matrix (Roque 2011).

In the 18th century, Pope Clement XIV, under the direct influence of Joaquim Winckelmann, the founder of art historiography and the Vatican's librarian, began the construction of a museum where the precious art collections preserved by the Popes over the centuries could be exhibited to the public (Valeri 2020). The museum was completed in the papacy of Pius IV and is an example of the universalist museums that mark the beginning of the history of museology.

At the end of the 18th century, as a concept and organisational structure, the museum's institution coincided with the progressive secularisation of society, which led to the depreciation of many collections of religious origin. The recognition that liturgical objects express the excellence of artistic production over time has led to them being considered the explicit documents of art history as objects with heritage and artistic value. Museums have integrated liturgical and devotional objects into their collections, recruited them as works of art, and displayed them in an undifferentiated way alongside other artefacts and works of art (Roque 2011). This occurrence marks the pioneering conversion of a sacred or religious object into a museological object.
