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 so much on its architecture but on its art, and rightly so. Painting and sculpture have a way of bringing us into contact with the Divine. 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, the ceiling frescoes by Michelangelo Buonarroti, commissioned in 1508 by Pope Julius II. People called him “il divino” because they felt that Michelangelo brought them into contact with the Divine.

Yet, we should not overlook the architecture of the Sistine Chapel. It is crucial to our understanding of Michelangelo’s masterpiece. First of all, the paintings on the walls of the Sistine Chapel include cities, temples, and triumphal arches in the story of Moses and of Christ, yet architecture is essentially nonexistent in the backgrounds of Michelangelo’s paintings. Instead, he carried the proportions and dimensions of the room up into the ceiling to create 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 that 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 new 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, he would later work on the new Saint Peter’s. He is credited with designing this “greatest dome in the world,” which was completed 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 of people each year. The chapel is connected to the papal apartments and offices and is located right next to the basilica where Saint Peter, the first pope, is buried. The Sistine Chapel is at the crux between the palace of the pope 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 of three of the patriarchal basilicas in Rome. On the outside, it is a simple brick building with a fortress-like crenulation at the top, intended as a place for archers 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 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 were used for daily Mass. The first conclave for the election of a pope held in the Sistine Chapel was in 1492, and it has been the location of every conclave since 1878.

For Mass, the chapel needed a sanctuary for the altar, a chair for the pope and seating for the papal household. 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 Giovanni Pierluigi da Palestrina as a member in the 1550s. Many members of the papal household sat around the walls or on the stairs. A chancel screen was built to separate the papal household from the laity. 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 was built with sixteen tall clearstory windows and a flattened barrel vault ceiling.

Between 1473 and 1481, Pope Sixtus IV had this chapel built to replace the Cappella Magna, or “Great Chapel,” which may have been built by Pope Innocent III in the early thirteenth century, which had become decrepit over the centuries. The Sistine Chapel was built on the foundations of the “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 the arts, Sixtus founded the Biblioteca Vaticana, created the first public museum (at the Capitoline Hill), restored hospitals, and built a series of churches dedicated to the Virgin Mary.

Because it was in terrible structural condition, previous popes had begun to renovate Saint Peter’s Basilica. In the 1400s, some of the thick walls were visibly leaning, and the structure was coming undone at the roof. Sixtus wanted to build a new chapel in honor of the Immaculate Conception behind the main altar. Then, he wanted to rebuild the Great Chapel next to Saint Peter’s and dedicate it to the Assumption of the Virgin.

Baccio Pontelli and Giovannino de’ Dolci are the two architects associated with the Sistine Chapel. It was built in eight years and decorated by the finest artists from Tuscany and Umbria. The architectural design determined the layout of the paintings by Perugino, Botticelli, Ghirlandaio, and Signorelli. In turn, the architecture of the chapel and the composition of the paintings influenced the layout of the ceiling panels by Michelangelo. Originally, the barrel-vaulted ceiling was covered with the heavenly constellations, painted by Piermatteo da Amelia.

Sixtus’ iconographic layout was inspired by the chapels of the Early Renaissance, such as the Cappella Scrovegni in Padua by Giotto (1305), 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. Other 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 Niccoline at the Vatican by Fra Angelico, frescoed just twenty-five years before the Sistine Chapel. Commissioned by Pope Nicholas V, the Niccoline 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 twenty-two foot grid of twelve squares. 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. The first and tallest level is nineteen feet tall and includes built-in benches and painted tapestries. The second level is fifteen feet tall and is where the paintings of the life of Christ on one side and the life of Moses on the other are located. All four of Sixtus IV’s painters—Perugino, Botticelli, Ghirlandaio, and Signorelli—were involved in these paintings. The third level is fourteen feet tall and consists of thirty-two early canonized popes, mainly martyrs. The fourth level is around ten feet tall and includes the forebears of Christ on either side of the windows painted by Michelangelo. His main paintings, however, were on the vaulted ceiling, which begins approximately eight feet below the top of the vault, bringing the total height of the chapel to sixty-eight feet.

Horizontal cornices, some real and some painted, create these four levels, while pilasters, both painted and real, determine the width of the images. For example, the tapestry panels on the first level are generally eighteen feet wide by sixteen feet tall, while the paintings of Moses and Christ on the second level are eighteen feet wide by thirteen feet tall.

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

Like Stations of the Cross, the life of Moses and the life of Christ both begin at the altar and proceed back 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—the 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 of Moses as a precursor to the Messiah and Christ as a second Moses. The two final paintings in the sequence end on the east wall above the entrance door.

At the time of Sixtus IV, there was also a fresco above the altar by Pietro Perugino, the teacher of Raphael. It was a painting of the Assumption, which was the dedication of the chapel. Scholars believe that this Assumption altarpiece, destroyed by Michelangelo when he painted the Last Judgment, may 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 Pope Sixtus IV, hired Michelangelo to beautify the Chapel. He felt the need to redo the ceiling, due in part to the large crack that 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 Buonarroti 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 through the flood, so the geometry of the room’s horizontal and vertical elements directed his painting of the ceiling architecture. Just as some of the original pilasters and cornices of the walls were fictive, so were all of Michelangelo’s architectural elements on the ceiling. 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 remunerated better than any other artist in the world when he painted this ceiling. He was thirty-one years old and already considered a master.

In a letter from 1523, written after the ceiling was finished, Michelangelo stated that the Pope asked him for a painting of the twelve apostles. But Michelangelo believed it “would turn out a poor thing,” and the pope gave 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 related to the windows below, next to which he included figures on thrones, later the prophets and sibyls. His second design placed large octagonal paintings over the windows and smaller rectangular panels in between. These were smaller than the panels by Botticelli and Perugino on the walls below.

This led to the third and final design in which the ceiling was divided up equally by ribs. The space between the ribs was similar to the width of the window below. Michelangelo took the geometry of the wall below and continued it up into the ceiling. However, because of the corner vault, he could not put large panels on the ends of the ceiling. If he had followed the geometry of Perugino and Botticelli below, he would have had only four big panels on the ceiling. Instead, by doubling the ribs he found a way to get nine panels. The long walls below have six windows, six paintings, and six tapestries. Michaelangelo sacrificed the size of the panels so he could tell a more elaborate story. The alternation of rectangular and square frames reinforces the architecture of the room, since Michelangelo’s large paintings are centered over four of the windows, and the small paintings are centered over the pilasters below. The large panels of Michelangelo’s ceiling are images eight feet by fifteen feet, and the small panels are six feet by eight feet. The pedestals and ribs surrounding the paintings seem to create depth in a trompe-l’œil manner, to better emphasize the story of creation.

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

The architecture of the chapel and walls below, both fictive and real, continues 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 on level one between the tapestries and level two with the lives of Moses and Christ. Above levels two and three there are real cornices. Both real and fictive—solid and trompe-l’œil, stone and paint, are 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 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. Michelangelo followed the Renaissance custom of transforming the candelabra and flaming bowl of early Rome into balusters of the 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 upon which he painted four 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 the 300 figures and landscapes.

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 altarpiece of the chapel’s dedication, the Nativity and the Finding of Moses on the second level, and the two windows and four popes on the third level. Twenty-five years later, under Pope Clement VII (Medici), Michelangelo returned to Rome 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 on the upper walls in 1508.

The chapel was originally intended to have an altar wall harmonious with the other walls. But when visiting the Sistine today, the Last Judgement is often what people notice first. It is a huge painting, fourty-four feet wide by sixty 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 also had a baldachin and a large altarpiece placed in front of the Last Judgment. The altarpiece was a tapestry and could be changed depending on the feast day. In the 1940s, this baldachin and tapestry were removed to better see the Last Judgment, which unfortunately also decreased 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 a great amount of art and painted architecture, which has intensified the experience of the chapel. The architectural elements of the Sistine Chapel are the frames and supporting actors for the main narrative: the creation and fall of the world, the redemption of Christ, and the founding of the Church, which continues its mission until Christ returns at the Last Judgment.