New research into the Baptistery 

New research into the Baptistery 

Who built the monument, when and why?

Tue 28 May 2024 4:30 PM

Draw a circle enclosing the old city walls of Florence and at the very center you’ll find the Baptistery of San Giovanni, a holy place where children are baptized, a symbol of civic unity and fiorentinità, a miraculous work of architecture, and an enigma. Who built it, when and why? 

It’s a Romanesque building in Florence that, inside and out, imitates elements of the Pantheon in Rome. Its classicism is so strong that it was long mistaken for an ancient construction. Now it’s sometimes qualified as a “proto-Renaissance” work of Romanesque architecture. Buildings from this period in other Italian cities rarely emulated Roman architecture and never as closely, comprehensively and artfully as the Baptistery. As the German art historian Walter Paatz wrote, “Basically, it cannot be compared with anything.”

For Brunelleschi, the Baptistery was a model of excellence, as were Santi Apostoli and San Miniato al Monte, also suffused with classical elements. Without them as examples, would he have approached architecture the same way? Could he have convinced Florentines that the architectural language of pagans could serve modern Christian worship? These three churches, each sublime in its own way, played an important role in the Renaissance starting where it did.

Open a guidebook, textbook or Wikipedia page on the Baptistery and you’ll see two key years associated with its history: 1059 and 1128. Scratch the surface and you’ll learn that both come from a handsome 1684 book called Firenze Città Nobilissima by Ferdinando Leopoldo Del Migliore, an acolyte of the great Florentine antiquarian Carlo Strozzi. Learned Florentines immediately noted that Del Migliore’s history contained many errors (more recently outright fabrications have been detected), but the volume gradually acquired the sheen of age and some of its “revelations” seeped into accepted knowledge about the Baptistery. Del Migliore’s tortuous prose seemed to suggest that Strozzi had found one document attesting to the consecration of the Baptistery in 1059 and another to the installation of a baptismal font in 1128.

I recently published previously unknown documents from the Biblioteca Nazionale and Archivio di Stato that make plain Del Migliore’s mistakes and misinterpretations on this subject, and demonstrate that the two events long at the center of Baptistery studies never happened. But if 1059 and 1128 are red herrings, what do we know that can help unravel the origins of the Baptistery?

View of the Baptistery’s main facade from the east. Ph. Saliko via Wikipedia

Fortunately, there’s some good physical and visual evidence. Similarities between the masonry technique and architectural style of the lower levels of the Baptistery, Santi Apostoli and certain parts of San Miniato suggest their near-contemporaneity. While no eleventh- or twelfth-century documents related to the Baptistery survive, contemporary records do allow us to date the other two churches to the 1070s. Further, radiocarbon dating of charcoal fragments discovered beneath piazza del Duomo during its excavation 50 years ago pointed to a large building project in the early 1070s. Scholars assumed the Cathedral had undergone an undocumented renovation, fooled by Del Migliore’s dates into thinking the Baptistery couldn’t be involved.

What makes the early 1070s even more attractive for the origins of the Baptistery is that the historical context fits. In the 1060s Florence had torn apart as a religious community. Vallombrosan monks accused bishop Pietro Mezzabarba of corruption and turned the people against him. In this period, infant baptism in cities was supposed to take place in a large ceremony on Holy Saturday presided over by the bishop, but Florentine parents who had lost faith in Bishop Mezzabarba’s ability to sanctify the anointing oil turned to priests instead. The pope, lacking proof of corruption, defended Mezzabarba, so in 1068 the monks turned to a higher authority, asking God to show the truth in a trial by fire. When one of the brothers walked through a wall of flames unharmed, Mezzabarba’s support crumbled and his tenure came to an end. As the 1060s ended and the 1070s began, therefore, Rome needed to restore Florentines’ faith in the church and re-establish the community ritual of baptism.

Papal fingerprints are on the Baptistery in other ways, too. The monumental window treatments on the outside and columned niches on the inside clearly emulate the Pantheon, already long used as a church. It was not, however, officiated daily, but reserved for high-holiday Papal masses, part of a small group of the most extraordinary Roman churches. I believe that the architect of the three Florentine churches came from the Pope’s entourage because previous Florentine architecture shows little interest in antiquity and because the plan of San Miniato closely echoes that of Santa Maria in Portico, a Roman church consecrated by Pope Gregory VII in 1073 (now demolished). Its altar, an ancient Roman ara repurposed for Christian use, still exists. Abundant evidence shows that Pope Gregory and his circle were fascinated by the Roman Empire and believed that the papacy was its heir. The Pope could thus claim supremacy over the German emperor, with whom he increasingly clashed.

Reconstruction of piazza del Duomo c. 1150. The Baptistery would likely have commanded more attention than the old Cathedral of Santa Reparata. Credit: Domenico Cardini + Riccardo Righini

As the capital of the March of Tuscany, Florence had remarkable rulers in the early 1070s: Matilda of Canossa and her mother, Beatrice. Given the obvious expense and artistic ambition of the Baptistery—it probably outshone the old cathedral of Santa Reparata—one or both likely served as patrons, along with Pope Gregory and the new Florentine bishop Ranieri. Behind such an extraordinary building it seems natural, even inevitable, that there were extraordinary people.

At the literal and symbolic center of Florence is an embodiment of a “proto-Renaissance” that, in this new interpretation, sprang from Rome, supported by the brilliant rulers of Tuscany. The Baptistery of San Giovanni made our city fertile ground for the great cultural movement that centuries later would expand from the banks of the Arno to sweep the world.

If this piece interests you, read the full article (‘Fiorenza figlia di Roma’: New Light on the Baptistery of San Giovanni and the Chronology of Florentine Romanesque Architecture’) in the new issue of the Kunsthistorisches Institut journal, Mitteilungen des Kunsthistorischen Institutes in Florenz

Related articles


Revelations exhibition at Museo Sant’Orsola

Juliette Minchin and Marta Roberti display impactful art in the former city-centre convent.


Jacopo di Cione’s Madonna della Neve altarpiece restored

Friends of Florence fund restoration and relocation of Renaissance work.