THE BRUNELLESCHI’S DOME OF THE FLORENCE CATHEDRAL

The Dome ( Cupola ) of the Florence Cathedral by Brunelleschi

The cathedral’s dome or Brunelleschi’s Dome, designed by Filippo Brunelleschi, is still today the largest masonry dome in the world. Let’s discover its fascinating history and the ingenious techniques devised to create this engineering masterpiece.

History of the Cupola of the Florence Cathedral

When the Santa Maria del Fiore church was completed in 1315, the dome above the choir did not yet exist due to various technical challenges.

One of these challenges was related to the construction of wooden centering, which essentially consisted of arched scaffolding that facilitated the shaping and support of the dome under construction. However, due to the size of the dome, this approach proved unsuitable for the project.

In 1420, following a public competition, Filippo Brunelleschi and Lorenzo Ghiberti were entrusted with the direction of the construction site, although the latter still needed to complete the work.

With the structure’s completion in 1436, Pope Eugenius IV officially consecrated the cathedral.

Brunelleschi’s design was reminiscent of the one hypothesized by Arnolfo di Cambio, the architect who conceived the cathedral. A fresco from 1355 located on the vault of the “Cappellone degli Spagnoli” in the church of Santa Maria Novella depicts the cathedral’s dome with similar forms.

The architecture of the Brunelleschi’s Dome (Cupola) of the Florence Cathedral

Brunelleschi‘s incredible dome has an internal diameter of 45.5 meters while reaching 54.8 meters on the outside. Given these truly exceptional dimensions, it is considered an impressive architectural feat, especially considering the era in which it was executed.

Brunelleschi had to solve numerous dilemmas regarding his design’s feasibility, stability, and safety. The dome appears octagonal from the outside and comprises two overlapping and self-supporting shells separated by a 1.20-meter-wide gap.

Using the golden ratio, which was popular during that time and considered balance and harmony, Brunelleschi achieved his goal but implemented some construction techniques.

He calculated the exact inclination of the walls and established the herringbone arrangement of the bricks to prevent them from falling. The external ribs and the upper lantern also contributed to the structure’s stability, counteracting the forces that could cause the dome to collapse.

For this reason, the internal octagonal drum is raised to another level, where the so-called “eyes” are visible. These eight circular windows illuminate the underlying choir and apse area.

FRESCOES OF BRUNELLESCHI’S DOME

Initially, the interior decoration of the Brunelleschi’s Dome was supposed to be created with golden mosaics. However, their excessive weight, exorbitant costs, and stylistic preferences of the time led to a different decision.

Cosimo I de’ Medici decided to begin the works in 1572, during the Mannerist era. He entrusted the task to Giorgio Vasari, who only completed the final round around the oculus. Federico Zuccari, his disciple, and other artists completed the works in 1579. At that time, it was one of the most significant symbolic cycles in the world.

The overarching theme is the Universal Judgment, illustrated on the dome, which is divided into eight sections, further divided into six registers. Each sector represents choirs of angels, saints, virtues, and beatitudes. The prominent figure is the large depiction of Christ with the Madonna and Saint John the Baptist.

There are also allegorical figures of the time, contemporary personalities, including the Medici family, the emperor, and the King of France, and artists like Vasari and Giambologna.

LANTERN OF THE FLORENCE CATHEDRAL

The impressive Brunelleschi’s Dome of the cathedral is crowned by the lantern, also designed by Brunelleschi, who, however, passed away before its completion. The works, initiated in 1446, were finished by Michelozzo and other artists in 1461.

Above the lantern is a large golden sphere designed by Verrocchio. The hollow sphere, with a diameter of two and a half meters, is accessible from the inside for technicians to inspect its physical condition. At the highest point of the cathedral, there is a large golden cross, reaching a height of 116 meters.

Since its inception, the golden sphere has been subjected to adverse weather events. In 1601, it was struck by a lightning bolt so forcefully that it fell onto the square below. Even now, the impact point is marked by a white marble slab.

On the outer octagonal perimeter of the dome, one can notice the unfinished walkway by Baccio d’Agnolo. When Michelangelo was asked to express his opinion, he criticized it so much that the artist refused to complete it. That’s why this architectural part of the church still appears rough.

VISITING BRUNELLESCHI’S DOME

Guided tours of Brunelleschi’s dome begin at the Porta della Mandorla, on the side of the cathedral. Climbing the steep spiral staircase with 463 steps, visitors reach the inner terrace of the dome.

The dimensions and height are dizzying in every direction. One can see the choir area and the spectacular marble floors while looking up, revealing Vasari‘s magnificent Judgement Day fresco.

The path only follows part of the dome‘s perimeter because, at a certain point, it enters through a small door and leads into the gap between the two overlapping domes.

The ascent continues, literally climbing the inner dome and following its sloping profile. Finally, visitors emerge onto the panoramic terrace of the upper lantern, from which they can admire the entire city of Florence and truly understand that the town is nestled among the Tuscan hills.

The reddish colors of the roofs and the winding streets are fantastic to behold. Ancient palaces, monuments, churches, and parks can also be seen in the distance.

This is truly an unforgettable experience when visiting Florence, a magnificent city of art.