Brunelleschi and the Ancient Sacristy in the San Lorenzo

We now walk left into the transept arm and pass through the door leading to the Ancient Sacristy: a sacristy, or burial chapel, that was fully designed by Brunelleschi.109 The sacristy was built between 1422 and 1428. The latter year is still written in the lantern. The project was greatly admired even during the time of its construction. According to Manetti, it exhibited such character that it ‘surprised everyone with its new style’ 110 Giovanni di Bicci de’Medici  tombe insisted that the sacristy be completed before his death. For the story about Donatello (tondi and the doors) and the ancient sacristy, please click here.

Tomb Giovanni di Bicci de’Medici Ancient sacristy San Lorenzo
Youtube Khan Academy Brunelleschi Ancient Sacristy (4.01 minutes)
tomb Giovanni di Bicci de’Medici ancient sacristy San Lorenzo

Brunelleschi had an unlimited budget at his disposal. If you stand in the sacristy, you will notice how the choir area with the altar lies two steps higher. For an area this sacred, this does not come as a  surprise. Next to the choir area, you will notice two doors that each lead to a separate room with barrel vaults. The room to the right is a staircase that leads to the crypt, but also to the top of the sacristy. The room to the left, behind the door, is a washing area for the priest preparing and dressing for the mass. These rooms are each one step higher than the large main room.

Ancient sacristy
old sacristy San Lorenzo Brunelleschi

From an overall perspective, we notice that Filippo clearly distinguished the separate parts from each other, but also managed to establish a clear connection. He achieved the latter in part by using an entablature, which continues into the choir area with the altar. In addition, the Corinthian pillars continue through the corners where they turn into arches in the lunettes. The pilasters in the corners of the choir have only one fluting, while the corner pilasters in the main area have three. The three naves in the area of the altar stand apart from the walls in the main room, just like the small round dome. The load-bearing elements are clearly accentuated. As we have already seen in the church and at the Ospedale degli Innocenti, Filippo used a blue-grey pietra serena for the load-bearing parts. The walls, on the other hand, are a white plaster, making it seem as if the wall planes between the blue-grey pilasters, consoles and the entablature are dissolving. From the corners of the cube, the pilasters continue their way up, interrupted by a horizontal band, the entablature, to then change into semi-round arches that support a round ring. This ring, in turn, supports the large dome. This upward movement is continued by the twelve ribs of the large dome. The walls themselves are lacking pilasters. The lunettes have tondos at the highest point. Only the windows seem to be affected by gravity, slightly slowing down the upward movement of the load-bearing parts.

Brunelleschi uses three kinds of vaults: the aforementioned barrel vault in the two small rooms, a round small dome in the choir area and a sizable folded dome with twelve ribs. Looking closely, you can see that the round ring where the folded dome (once called an umbrella dome), consists of a folded and tied tarp.

vaults ancient sacristy
vaults ancient sacristy Brunelleschi San Lorenzo

The planes between the ribs of the folded dome are bulging with the wind they appear to be catching. The folded dome appears to be floating, and this effect is amplified by the twelve round windows that let through the light. The ribs nonetheless receive additional support, but this is only visible on the outside of the building. A small wall with twelve recesses for the windows is simultaneously supporting the ribs.

Light in the Ancient Sacristy

Brunelleschi’s use of lighting in his buildings is well thought out. The room we are now standing in shows how equal the light is entering it. Filippo achieves this by placing all windows high-up on an equal line. The windows are placed exactly above the entablature that runs through the entire space. The entablature thus also turns into a window sill. This is entirely in accordance with Florentine tradition, as you can see with the coloured marble strips below the windows at the Baptistry.

interior ancient sacristy and exterior windows
Ancient Sacristy San Lorenzo Brunelleschi

The windows above the two doors receive indirect light because of the windows in the small back rooms. The placement of the two windows in the back wall of the small rooms was not so much to achieve lighting in those rooms, but instead for the larger room. Lighting the dome was not much of a problem: the twelve round windows are letting in an equally spread light. The same cannot be said for the lantern, not a lot of light was allowed to fall through it or else the centre part of the sacristy would receive too much light. Due to the equal lighting he set out to achieve, Brunelleschi likely opted for a folded dome with a small round lantern and twelve oculi.111

Lantern of the Ancient Sacristy

The lantern is remarkable and based on a small tholos with six fluted Corinthian columns. The columns that Filippo used for the lantern support a complete entablature: architrave, frieze closed with a cornice. On top of that, a strange spiral shape that is reminiscent of an owl. Naturally, all of this is crowned with a cross. Right in the centre below the lantern lies the grave of Giovanni di Bicci de’Medici and his wife.

Lantern of the Old Sacristy San Lorenzo Brunelleschi

Above the sarcophagus sits a table with a porphyry round plate in the middle and the unmistakable emblems (six pills) of the Medici. Incidentally, this table was also used by the priests. It looks like a mensa, an altar surface that usually stored saint relics underneath.

The circle, the square and the proportions of the Ancient Sacristy.

The design of the sacristy used the two basic geometric shapes: the square and the circle. Each side of the square has a length of twenty braccia, or 11. 67 cm. Adding the dome, the sacristy has three floors.  These floors each make for a perfect cube. The combination of a square and circle seems very familiar to the drawing by Leonardo da Vinci that he made for Fra Luca Pacioli. For the drawing, Leonardo based himself on the description by Vitruvius that we mentioned before.112 The circle is repeated multiple times in the semi-arches above the walls, in the tondos, the dome and finally in the round shape of the lantern. All in all, the chapel gives off a stable yet mobile impression. (click here for a layout and cross-section) Regarding the proportions of the sacristy, the above mentioned trichotomy is based on a geometrical ratio that was custom in medieval galleries.113 As we have already seen, this was also the case at the Ospedale degli Innocenti. In the sacristy, the fixed size was the diagonal of the room, namely 11.59 cm.

Baptistery in Padua and the Ancient Sacristy

Filippo Brunelleschi never visited Padua, at least according to documented sources. For instance, Manetti but also Vasari do report on Filippo staying in Rome, but Padua is never mentioned. Still, there are reasons to believe Brunelleschi did actually visit this city, or at least knew it’s Baptistery quite well.

Baptistery Padua
Baptistery Duomo Padua

Because as it turns out, there are striking similarities between the baptistery in Padua from 1260 and the Ancient Sacristy built by Brunelleschi, like

1. A pendentive dome
2. A choir with dome
3. Square layout and three rooms: a choir room with two adjacent rooms, each with barrel vaults.
4. Each side of the square is exactly 11.67 cm in Padua as well  as in the Ancient Sacristy.
5. Cube shape with dome and an adjacent small cube (choir area again with a dome).


Giusto de’Menabuoi Baptistery Duomo Padua
Giusto de’Menabuoi Baptistery Duomo Padua

It should also be mentioned that a visit to the Baptistery in Padua is more than worth your time, particularly because of the fourteenth-century frescos by the Florentine painter: Giusto de’Menabuoi. What is unique is the elaborate way in which Giusto paints the subject in the choir area, the dream or better put, the nightmare of John: the demise of the world. Wikipedia has pictures of Giusto’s frescos. Brunelleschi even partly translated the painted mouldings by Giusto into real classical pilasters and arches. A ducento room with trecento frescos was transformed by Brunelleschi into Renaissance architectured .115

Another source, but closer to home, is the Baptistery in Florence. The mosaics of the dome quickly show the ribs, pendentives and folded vault.116

The Ancient Sacristy: Renaissance or Gothicism?

The Ancient Sacristy may be a Renaissance building, but the load-bearing structure from the ground up to the top of the lantern that runs through pillars and ribs up to the washer, is a Gothic principle. Such Gothic constructions can be found at the chapels in the apse of the Duomo in Florence. It does require a certain nuance, as the ribs of the folded dome in the Ancient Sacristy are still being supported on the exterior by vertical styles. The load-bearing elements, however, do not have Gothic shapes, bundled pillars, but purely classical ones. In his biography about his friend Brunelleschi, Manetti spoke of ‘membri e ossa’, the bones of a skeleton that carry the body like parts of pietra serena carry Filippo Brunelleschi’s architecture.117 Alle tektonische of dragende delen, de botten, worden met de blauwgrijze pietra serena aangegeven.

The meaning of the Ancient Sacristy and the altar

The meaning of the sacristy is rather conventional.118 The altar that is clearly based on the altar in the Baptistery has four semi columns with panels in between. The centre-most panel showed the sample panel of the person who designed by Ancient Sacristy: Brunelleschi with his ‘Sacrifice of Isaac‘. We will look at this bronze relief on the day dedicated to sculpting, in the Bargello, and compare it to Ghiberti’s sample panel.

Ancient Sacristy altar
Ancient Sacristy altar San Lorenzo Florence

The sides of the altar displayed a relief of Ezekiel and Isaiah and at the front Daniel and Jeremiah. Above the altar now hangs a wooden cross from the fifteenth century. The sacrifice of Isaac is of course a prefiguration of the crucifixion. The Old Testament was interpreted as being a hidden agenda that the future: the New Testament, already announced. Isaac’s father, Abraham, was willing to sacrifice his son for the love of God. And thus God the Father also allowed his Son to die by crucifixion, which in turn saved humanity. The four prophets are again prefigurations of the four evangelists in the tondos in the lunettes of the main room. The four evangelists have been placed on the main axes. Furthermore, they are also emphasised by the ribs of the folded dome that are perpendicular to the wall planes. The tondos on the pendentives, on the diagonal axis, display the life of John the Baptist. Not entirely coincidental, given how John the Baptist is the patron saint of Florence. The tondos were planned from the onset.119

Cosimo, who was rather fond of decorations, ordered Donatello to add reliefs to the tondi and the door panels. We will further discuss and examine these on the day we cover sculpting, when we visit this church and both sacristies (old and the new). Manetti describes in his biography about Brunelleschi how we got into a fight with Donatello about the decorations of the Ancient Sacristy. We will further discuss this on the day we cover sculpting, when take another look at this room (click here if you want to read and view the story about decorations in the Ancient Sacristy). The location of these tondos mean that they are more than just ornaments. The nineteenth-century Ruskin, but most notably the twentieth-century architect Alfred Loose were adamantly against using old ornaments. The tondos used for this room are not so much ornaments as they are a marking of the room, to which Donatello later added a narrative relief. In the words of Castex:

‘Horizontal circles and vertical semi-circles describe the bisectors of the room and rotate around the axis of the large dome, the medallions swarm out and attach themselves to all ribs, even to the daring crossing of the pendentive of which they indicate its slanted position.’

Jean Castex, ‘De architectuur van Renaissance, Barok en Classicisme Een overzicht 1420-1720, Sun, Nijmegen, 1993 p. 56

We exit the church. The facade that was designed by Michelangelo Buonarroti, but which was never constructed, the New Sacristy and the library in the cloister that were actually constructed, will be discussed later when we approach the end of our architecture walks.

The style of contemporaries and architects: Michelozzo and Brunelleschi

Michelozzo clearly differs in style from Filippo Brunelleschi.120 Brunelleschi was an expert in constructions and not just gothic ones as his biographer and contemporary Manetti noted, but: ‘He studied the excellent and ingenious construction methods from Antiquity and their musical proportions.’121

Michelozzo portrait from the Crucifixion of Fra Angelico

After losing out on the doors of the Baptistery, Brunelleschi was so offended that he said his farewell to sculpting. Together with his friend sculptor, Donatello, he left Florence and spent many years in Rome. Here, he devoted himself fully to architecture and he made many interesting discoveries like masonry types and the ulivella: a tool to hoist heavy natural stone. Many classical ruins and buildings were measured. They used a kind of checkered paper to get the right scale and perspectives for the building or ruin on paper. Brunelleschi invented perspective, while Alberti had already described this style of drawing to suggest actual depth on the flat surface.122


The knowledge gained by Brunelleschi in Rome was used, along with his knowledge on gothic constructions, to construct the dome. Filippo had not only performed archaeological research, but he was well versed in classical rules. The same cannot be said for Michelozzo, he used a wish wash of elements that to him seemed like all’antica. And on occasion, he would fall back on his fantasy. He did not use the true canon of classical art. He maintained a more eclectic style. What’s more, he deeply loved gothic details. Michelozzo regularly used the groin vault, like with his library in the San Marco. While Brunelleschi often used as little different elements as possible, like one type of capital or one type of pediment, Michelozzo instead used many different ones. This shows particularly at the tabernacle in the San Miniato al Monte, where Michelozzo used a resounding four different capitals. According to him, this only made the building more spectacular. Cosimo, who awarded Michelozzo the assignment, must have liked this idea. Furthermore, Michelozzo was a very pliable and pragmatic architect. As opposed to Brunelleschi, who was much more rigid. This might also explain why Michelozzo was not too bothered by ‘the faulty corner solution’ in his Palazzo Medici-Riccardi.

Next day 2 continuation-5