Michelangelo and the Architecture of the Sistine Chapel

by Duncan G. Stroik, appearing in Volume 47

What is the most famous chapel in the world? Many would say the Sistine Chapel in Rome. When pilgrims and tourists visit the chapel, the focus is not on its architecture but on the art, and rightly so. Beautiful art has a way of bringing us into contact with the Divine more than other arts, with the possible exception of music. It is the art, more than the architecture, that we relate to, we who are created in God’s image. This creation story is marvelously shown in the most famous part of the Sistine Chapel’s art, the ceiling frescoes by Michelangelo Buonarotti, commissioned in 1508 by Pope Julius II. People called him ‘il divino’ because they felt that Michelangelo brought them into contact with the Divine through his art. 

Yet, we should not overlook the architecture of the Sistine chapel. It is crucial to our understanding of Michelangelo’s masterpiece. Unlike the earlier paintings on the walls of the Sistine Chapel, which included cities, temples, and triumphal arches in architectural perspective in the story of Moses and of Christ, architecture does not have the same presence in the landscapes of Michelangelo. Instead, he filled the Sistine Chapel with painted fictive architecture derived from the real architecture of the chapel. He carried the proportions and dimensions of the room up into the ceiling to create a series of fictive architectural frames for the story of creation. Michelangelo derived his design for the frames directly from the windows, cornices, and pilasters already existing in the chapel. But as he was wont to do, he modified the architecture and made it his own. 

History of the Sistine Chapel

Located just north of Saint Peter’s Basilica, the Sistine Chapel would have been visible from the Piazza di San Pietro for the first hundred years after it was built in 1481. Today, however, it is blocked by Bernini’s colonnade, the façade of Saint Peter's, and the Vatican Palace, which includes the Vatican Museum. Although Michelangelo’s most famous work was done on the inside of the Sistine Chapel, later he would revise the plan of new Saint Peter’s. And he is credited with designing this "greatest dome in the world," although it was not completed until twenty-six years after his death. 

The Sistine Chapel itself is the private chapel of the pope and is used for sacred liturgy, for papal meetings, and the secret conclaves where the Cardinals elect a new pope. It is also the highlight of the most famous museum in the world, visited by millions each year. The chapel is connected to the papal apartments and offices, and is located right next to the basilica where the first pope, Saint Peter, is buried. The Sistine Chapel is at the crux between a bishop’s palace and the greatest temple in the world. 

The Sistine Chapel is located on the third floor of a four-story wing of the Apostolic Palace. Like Saint Peter’s Basilica, it is oriented backwards, with its altar on the west wall rather than in the east, which is true for three of the four patriarchal basilicas in Rome. On the outside, it is a simple brick building with a fortress-like crenulation at the top, which provided a place for bowmen to defend the Vatican. 

Built next to the original Saint Peter's Basilica, which was constructed in 324 A.D. during the reign of Constantine, the Sistine was the sacred place where the 200-strong papal household gathered for prayer with the pope. Old Saint Peter’s was used by the pope only a few times a year, the Sistine Chapel about forty times a year, and other smaller chapels for daily Mass. Since 1846, the Sistine Chapel has been used by the College of Cardinals for the election of the pope.

For papal Mass, the chapel needed a sanctuary for the altar, a chair for the pope and seating for the papal household around the walls. A choir loft off to the side held the Coro della Cappella Musicale Pontificia Sistina, famously led in the 1480s by Josquin des Prez and had Palestrina as a member in the 1550s. Many members of the papal household sat on the stairs. It also has a chancel screen separating the papal household from the laity and visitors. One of the few existing barriers remaining in a Roman church, the Sistine chancel screen was originally in the center bay of the chapel. The chapel originally had sixteen tall clearstory windows and a flattened barrel vault ceiling.

Between 1473 and 1481, Pope Sixtus IV has this chapel built to replace the Cappella Magna, or “Great Chapel,” built by Pope Innocent III there in 1298, which had become decrepit over the centuries. The Sistine Chapel is built on the foundations of that "Great Chapel" and is the same size in plan: 44 feet wide by 134 feet long. It became known as the “Sistine Chapel” after the death of its builder.  

Pope Sixtus IV was a Franciscan and an outstanding humanist. He was famous as a theologian and for his writings on the Immaculate Conception of the Blessed Virgin Mary. As a patron of art and architecture, Sixtus founded the Biblioteca Vaticana, created the first public museum (at the Capitoline Hill), restored hospitals, and built a series of churches all dedicated to the Virgin Mary. 

Because it was in terrible structural condition, previous popes had begun to renovate the original Saint Peter's Basilica. Some of the thick walls were visibly leaning, and the structure was coming undone at the roof. Sixtus wanted to build a chapel in honor of the Immaculate Conception behind the main altar. Then, he wanted to rebuild the Sistine Chapel and dedicate it to the Assumption of the Virgin. 

Baccio Pontelli and Giovanni de Dulci are the two architects associated with the Sistine Chapel. It was built in eight years and decorated by the best artists from Florence and Umbria. The design of the architecture helped determine the layout of the paintings by Perugino, Botticelli, Ghirlandaio, and Signorelli. The architecture and composition of these paintings influenced the layout of the later ceiling panels by Michelangelo. Originally, the barrel-vaulted ceiling showed the heavenly constellations, painted by Piermatteo da Amelia. 

Sixtus’ iconographic layout was inspired by chapels of the Early Renaissance, such as the Cappella Scrovegni in Padua by Giotto (1305), who is considered the first Renaissance artist. The interior of the Scrovegni Chapel has a series of scenes along the walls divided by painted architecture and a ceiling with blue and gold stars. The entrance wall of the Scrovegni Chapel is the Last Judgment, which Michelangelo would reprise on the altar wall of the Sistine in 1536-41. Two early Renaissance inspirations for the Sistine likely came from the 1384 Oratory of San Giorgio in Padua by the less well-known artists Jacopo d’Avanzi and Altichiero da Verona, and the 1451 Cappella Nicolini at the Vatican by Fra Angelico, which was frescoed twenty-five years before the Sistine Chapel. The Nicolini Chapel, like the Sistine, has a high altar, rich narrative paintings, a vaulted ceiling, painted tapestries on the walls, and a cosmatesque floor.

Architecture and Art of the Chapel

The Sistine Chapel is based on a simple geometrical layout. The interior of the chapel is 44 feet wide, 68 feet tall, and 134 feet long. If we divide the room based on the windows, we find a grid based on 22 feet. At the center of each square is a window, and the artwork is centered below the windows. If you do the math you realize the composition of the chapel is two squares wide by three squares tall by six squares long (44’:68’:134’).

The walls of the Sistine Chapel are divided into four levels, which are tallest at the bottom. The first level is 19 feet tall and includes built-in benches and painted tapestries. The second level is 15 feet tall and is where the great paintings of the life of Christ on one side and the life of Moses are located. on the other. All four painters — Perugino, Botticelli, Ghirlandaio, and Signorelli— were involved in these paintings. The third level consists of thirty-two early canonized popes. In most cases, they were martyrs. This level is 14 feet tall. The fourth level is 10 feet tall and includes the forebears of Christ in the lunettes surrounding the windows and were painted by Michelangelo. His main paintings, of course, were on the vaulted ceiling, which curves eight feet up above the lunettes, bringing the total height of the chapel to 68 feet.

Horizontal cornices, some painted and some real, create these four levels of painting, while the pilasters, both painted and real, determine the width of the panels. For example, the tapestry panels on the first level are generally 18 feet tall x 16 feet tall, while the paintings of Moses and Christ on the second level are 18 feet tall x 11 feet tall.

The pilasters on the walls are centered on either side of each window. There are six windows on each long wall and two on each short wall, yielding sixteen windows and sixteen pilasters on the third level. This is what determines the number and size of the sixteen tapestries on the first level and the life of Moses and of Christ on the second level. On the fourth level, there are thirty-two popes, two for each window. 

The life of Moses and of Christ narratives begin at the altar and proceed towards the entrance door. The story of Moses is on the south wall, while the story of Christ is on the north wall. Originally, there were two paintings on the west wall above the altar – baby Moses being found in the bulrushes on the left and Christ’s nativity on the right. The art and the layout reflect the theological symmetry between Moses and Christ. Moses is a precursor of the Messiah, and Christ is a second Moses. The two final paintings in the life of Moses and Christ end on the east entrance wall above the door. 

At the time of Sixtus IV, there was also a fresco above the altar by Pietro Perugino, the great teacher of Raphael. It was a painting of the Assumption, the dedication of the chapel. Scholars believe that this Assumption altarpiece, destroyed by Michelangelo when he painted the Last Judgment, would have looked similar to Perugino’s 1513 altarpiece for the Church of Santa Maria Assunta in Corciano, Italy.

In 1508 Pope Julius II, the nephew of the builder Pope Sixtus IV, wanted to beautify the Sistine Chapel. He felt the need to redo the ceiling, due in part to the fact that a large crack had developed down the middle of the vault in 1504. This gash in the heavenly ceiling was probably due to the settling of the building, which had been built in the same low area that caused the north wall of old Saint Peter’s to lean.

Michelangelo

Understanding the overall geometry and architecture of the chapel brings us to Michelangelo Buonarotti and his painting of the ceiling. Just as the earlier artwork of the life of Moses and Christ set the stage for Michelangelo’s frescoes of the creation story up through the flood, so the geometry of the room, its horizontal and vertical members, directed his painting of the ceiling architecture. Just as some of the original pilasters and cornices of the wall were fictive, so is all of Michelangelo’s ceiling architecture. The shape of the vaulted ceiling was a curved barrel vault with a flat top inspired by ancient Roman vaults discovered in the 1480s.

Art historians tell us that Michelangelo lived a frugal life, but we also know he was paid better than any other artist in the world when he painted this ceiling. He was thirty-one years old and was already considered a master. 

In a letter of 1523, written after the ceiling was finished, Michelangelo stated that the Pope asked him for a ceiling with the twelve apostles. But believing it “would turn out a poor thing,” the pope had given him permission “to do what I liked.” From 1508 to 1512, Michelangelo worked on the ceiling. His first design for the ceiling was similar to Medieval and Renaissance ceilings, which typically divide a ceiling into geometric panels of various shapes. In this design, Michelangelo’s panels relate to the windows below, next to which he includes figures on thrones, which became the prophets and sibyls. His second design alternates large octagonal paintings over the windows and smaller rectangular panels between. These are smaller than the panels by Botticelli and Perugino on the walls below. 

This led to the third and final design in which the ceiling is divided up equally with large ribs from wall to wall. The dimension between the ribs is similar to the width of the window below. Michelangelo takes the geometry of the wall below and continues it up into the ceiling. However, because of the corner vault, he could not put large panels in the ceiling at both ends. Thus, if he followed Perugino and Botticelli below, he would have had only four big panels. Instead, he found a way to get nine panels rather than four on to the ceiling. The long walls below have six windows, six paintings, and six tapestries.Michaelangelo sacrificed size to get more panels so he could tell a bigger story. The alternation of rectangular and square frames reinforces the architecture of the room, since Michelangelo’s large paintings are centered over the windows, and the small square paintings are centered over the pilasters below. The main panels of Michelangelo’s ceiling are images 8 feet by 15 feet, and the small panels are 6 feet by 8 feet. The pedestals and ribs surrounding them seem to create depth in a trompe l’œil manner, to better tell the story of creation. 

Michaelangelo fit prophets and sibyls around these scenes and put the ancestors of Christ in the lunettes below. Michelangelo was originally hired to paint twelve apostles on the ceiling, and he ended up painting 300 figures instead. 

The architecture of the chapel and of the walls below, both fictive and real, is continued into the ceiling. A marble rood screen with beautiful carving and grilles defines the floor of the chapel. It has square piers, which are repeated on the walls in painted form on levels one and two between the tapestries and the life of Moses and of Christ. There are real cornices above levels two and three; that is to say, it is both real and fictive—solid and trompe-l’œil, stone and paint, used together. 

Finally, we have Michelangelo’s fictive architecture on the ceiling. The sibyls are all women that gave prophecies foretelling the coming of Christ. They are surrounded by fictive furniture and inventive architecture. Behind each sibyl there is a pedestal that supports putti that are holding up the cornice, and they are reminiscent of the putti on the pedestals of the rood screen. Each of Michelangelo’s painted pedestals has balusters at the corners. These balusters look very similar to the choir loft rail at the mezzanine of the chapel. Michelangelo followed the Renaissance custom of  taking the candelabra and flaming bowl from Early Rome and transforming it into a railing. 

In the four corners of the ceiling, there were originally two intersecting vaults over the windows. Michelangelo combined these two vaults into one large pendentive panel in each corner which he painted with Old Testament scenes. Prophets alternate with the sibyls in the other pendentives. In the vaulting Michelangelo found a way to create new shapes using painted architecture. The fictive architecture of Michelangelo is there to reinforce the story being told by landscapes and figures. 

Altar Wall – Last Judgment 

When Michelangelo finished the ceiling, the altar piece of the Assumption was above the altar on the west wall, and frescoes of the finding of baby Moses on the Nile and of Christ’s nativity were above that. Today we have a very different experience. The fresco of the Last Judgment has taken up the whole wall, obliterating the Nativity and the Finding of Moses on the second level, the two windows and four popes on the third level, and the altarpiece of the chapel’s dedication. Under Pope Leo X (Medici), Michelangelo returned to Rome twenty-five years later and replaced the art and architecture commissioned by Sixtus IV with this grand painting of the Last Judgment. He even destroyed some of the ancestors of Christ he had painted previously on the upper walls. 

The chapel was originally intended to have a more subtle emphasis on the altar wall. But visiting the Sistine today, it is often what people notice first. The Last Judgment is a huge painting, 44 feet wide by 60 feet tall, which is thirteen times the size of the earlier paintings of Moses and Christ by Perugino, Botticelli, et al. Until the mid-twentieth century, the altar wall had a baldachin and a large altarpiece in front of the Last Judgment. The altarpiece was a tapestry and could be changed depending on the feast day. Since the 1940s, this baldachin and tapestry have been removed to better see the Last Judgment, but this has meant a loss to the altar’s prominence.

The existing architecture of the Sistine Chapel, both real and fictive, was crucial to Michelangelo’s composition of the ceiling. Il divino Michelangelo added more art and more painted architecture, which intensified the experience of the chapel. The architectural elements of the Sistine Chapel are the frames and supporting actors for the main narrative, which is the creation and fall of the world, the redemption of Christ, and the founding of the Church, which continues its mission until he returns at the Last Judgment.