The “Miracle” in Sant’ Ambrogio, which dates to around 1230, is one of the earliest documented eucharistic cults in Europe. What it celebrated was the idea of transubstantiation, the transformation of wine into blood during mass, and as such it underscored a basic plank of Church doctrine. However for parishioners like Giovanni, it was about much more than that.  The vial of warm blood, reputedly found after mass, was a kind of relic. Like the bones of a saint, it was an object where, to borrow from Peter Brown, heaven meets earth. These objects supercharged churches with holiness and prestige. They helped to define community – when they were displayed and especially when they were carried through the streets. They effectively sanctified urban space. In fact the Miracle relic became not only the focus of a neighbourhood cult but the centrepiece of the civic Corpus Christi parade, drawing in support from the powerful Guild of Judges and Notaries and, after 1425, from the government.

Given this, it’s no wonder the Benedictine nuns of Sant’ Ambrogio kept commissioning new chapels to house the relic. The one you see was finished in 1486. Is the figure at the door in Cosimo Rosselli’s fresco the bishop of Florence, as Giovanni says? Giorgio Vasari, the first art historian, certainly thought so 70 years later. But Vasari often winged it. If you ask the parish priest today, he’ll tell you the cleric with the relic is his fifteenth-century predecessor. It’s a more straightforward matter to explain the absence of the upper marker stone of the Red City potenza – that wasn’t put up until 1577.

As Giovanni says, his confraternity (of San Michele, with its oratory across the Piazza) had a key role in the Miracle procession. Confraternities were the ubiquitous face of lay associational life in Renaissance cities. They usually had tombs, sometimes a chapel, in a church for their brothers and sisters, and this allowed the commemoration of the dead. In the fifteenth century there was a big rise in the number of artisan confraternities. They provided a form of spiritual and social insurance: burial, dowries, sometimes subsidies in sickness and old age. They offered poorer Florentines a degree of agency, over both their lives and deaths. Apart from that, confraternities were seen – especially by the archbishop who approved their statutes – to play a role in instructing men in good Christian conduct. Gambling, taverns, and sodomy were usually banned. However, these kinds of prohibitions were often ignored.

David Rosenthal


To cite this essay, we suggest:
David Rosenthal, ‘Relics on parade’ published online 2013, in ‘Hidden Florence’, The University of Exeter,

Further reading:

Eve Borsook, ‘Cults and Imagery at Sant’Ambrogio in Florence’, Mitteilungen des Kunsthistorischen Institutes in Florenz, 25 (1981), 147-202

Peter Brown, The Cult of the Saints: Its Rise and Function in Latin Christianity (Chicago: University of Chicago Press, 1981)

Ronald Weissman, Ritual Brotherhood in Renaissance Florence (New York: Academic Press, 1982)