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Florence Duomo as seen from Michelangelo hill

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Florence Cathedral

Florence Cathedral is a huge church in Italy. It has a giant red dome on top. The dome was built from millions of bricks.

Florence Cathedral, called Santa Maria del Fiore, is the great cathedral of Florence, Italy. It was founded in 1296, and its enormous dome, designed by Filippo Brunelleschi, was built from 1420 to 1436 without a wooden frame to hold it up while it was built. It is part of the Historic Centre of Florence World Heritage Site.

The Cathedral of Santa Maria del Fiore was begun in 1296, when Arnolfo di Cambio, its master builder, laid the foundations. Its octagonal dome, built under Filippo Brunelleschi from 1420 to 1436 and crowned by a lantern placed in 1471, used more than four million bricks and is, Museo Galileo says, the biggest dome ever built without centring. UNESCO lists the cathedral first among the masterpieces of the Historic Centre of Florence.

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Photo: Petar Milošević, CC BY-SA 4.0, via Wikimedia Commons

Discover Florence Cathedral

Florence is a city in Italy.

In the old center of the city is a huge church called a cathedral. On top sits a giant dome with red tiles. It rises high above the rooftops.

Florence Cathedral stands in the historic center of Florence, a city in Italy. Its full name is the Cathedral of Santa Maria del Fiore. It was begun in 1296 by its master builder, the architect Arnolfo di Cambio, who laid the foundations.

Its most famous part is the dome. Designed by Filippo Brunelleschi, it was built between 1420 and 1436 from more than four million bricks. Visit Tuscany calls it the largest dome in the world at the time and still the largest ever built of masonry, which means stone or brick.

The cathedral is one of the monuments of the Historic Centre of Florence, inscribed on the World Heritage List in 1982; UNESCO names 'the Cathedral of Santa Maria del Fiore, the Baptistery and the Campanile of Giotto' first in its list of the city's universally renowned works of art. Universalis records that Arnolfo di Cambio returned to Florence in 1296 as the cathedral's capomaestro, master of works, and laid the foundations of the new building.

Museo Galileo dates the dome from the summer of 1420 to 1436, except for the lantern, and calls it the biggest dome ever built without centring, a wooden or iron structure to support the masonry while it is built. Visit Tuscany gives its diameter as 45.5 m.

Where
Historic Centre of Florence, Italy
Founded
1296; Arnolfo di Cambio, master builder, laid the foundations
Dome built
1420–1436 (lantern placed 1471)
Bricks in the dome
more than four million
Florence Duomo as seen from Michelangelo hill
Photo: Petar Milošević, CC BY-SA 4.0, via Wikimedia Commons

The biggest dome of its time

The builders planned a very big dome.

It was so big that many people doubted it could be built. Then an architect named Brunelleschi found a way.

The cathedral was begun in 1296, but its dome was started only in 1420. Its shape and size were already planned: an eight-sided dome about 45.5 meters across, close to the largest that anyone had ever built in brick.

In 1420 Filippo Brunelleschi was put in charge of building it, and work began that summer. Many people in Florence doubted his plan, but the dome was finished in 1436, apart from the lantern on top, which was put in place in 1471.

Visit Tuscany notes that when Brunelleschi was appointed in 1420 to continue the work, the general layout of the dome and its design were already in place, the work of his predecessors Arnolfo and Talenti, and that its internal diameter was near the maximum limit of any brick dome built at the time. Instead of reusing earlier solutions, he invented a technique drawn from ancient Rome's way of bricklaying and from medieval and eastern building.

According to Museo Galileo, the work began in the summer of 1420, Brunelleschi overcame the skepticism of his fellow citizens, and the dome was complete except for the lantern in 1436 and could be considered finished only in 1471, when the lantern was positioned using Brunelleschi's machines. Lightning damaged the lantern in the spring of 1601, and it was promptly restored.

Through the years

Herringbone bricks and two shells

Brunelleschi built the dome with no big wooden frame underneath.

He laid the bricks in a clever zigzag pattern. He also made new machines to lift heavy loads.

Museo Galileo says Brunelleschi built the dome without centring, a wooden or iron structure to support the masonry.

Visit Tuscany explains that he used bricks laid in a pattern called herringbone, which made the dome self-supporting. The dome has two shells, one inside the other: the lighter outer shell protects the inner one from the weather, and strong ribs join them. Brunelleschi also designed new machines to lift huge weights high up.

Museo Galileo explains that Brunelleschi built the dome without centring, devising ways to lighten the structure and to organize a worksite that kept the brick courses stable as their tilt increased from the base to the oculus. He designed his own machines to move and lift enormous weights; he left no drawings of them, but engineers such as Taccola, Francesco di Giorgio, Bonaccorso Ghiberti and Giuliano da Sangallo recorded them, and Leonardo da Vinci drew them in his notebooks.

Visit Tuscany describes the 'herringbone' bricklaying, drawn from ancient Roman, medieval and eastern methods, which made the dome a self-supporting structure. It has two pointed shells linked by ribs, the lighter outer one protecting the inner. Museo Galileo gives the curves: the inner shell's radius is 4/5 of the base diameter and the outer's 3/4, and estimates the dome's weight at 37,000 tons.

Dome, lantern, bell tower and a sunbeam clock

On top of the dome is a small tower called the lantern.

Next to the cathedral stands a tall bell tower. Inside, the dome is decorated with paintings.

The dome starts about 54 meters above the ground. On top sits the lantern, a small tower that, with its copper ball, is a little over 22 meters tall. Brunelleschi designed it, and it was built after his death in 1446.

Beside the cathedral stands the bell tower, which UNESCO calls the Campanile of Giotto. Inside, the dome is decorated with frescoes painted between 1572 and 1579 by Giorgio Vasari and Federico Zuccari.

Museo Galileo gives the dome's springing point about 54 m above the ground, a distance of around 35 m between opposite edges of the octagonal base, and a lantern a little over 22 m tall including the copper sphere. Visit Tuscany says the lantern, designed by Brunelleschi, was built after his death in 1446, and that the interior frescoes were painted by Giorgio Vasari and Federico Zuccari between 1572 and 1579.

The dome also served science. Around 1475 Paolo dal Pozzo Toscanelli made a gnomon in it, the highest built until then, which marked the moment the Sun passed the summer solstice; in the mid-18th century Leonardo Ximenes restored it and used it for astronomical and physical observations.

Dome diameter
45.5 m
Base of the dome
about 54 m above the ground
Lantern with its sphere
a little over 22 m tall
Weight of the dome
about 37,000 tons (estimate)
Florence Duomo as seen from Michelangelo hill
Photo: Petar Milošević, CC BY-SA 4.0, via Wikimedia Commons

The dome above the city

In the photo, the cathedral is lit up.

The big red dome rises above the dark rooftops. Hills stand behind it.

This photo was taken from Michelangelo hill, across the city. The cathedral is lit up: you can see the great dome with its white ribs and lantern, the long side of the church with its patterned walls, and the tall bell tower on the left. Dark hills rise behind, and the rooftops of Florence fill the front.

UNESCO says the historic center around it, 505 hectares inside the line of the old 14th-century walls, shows more than six centuries of art and building.

Taken from Michelangelo hill (the photo's title), the view shows the illuminated cathedral: the octagonal dome with its white ribs and round windows in the drum below, the lantern, the smaller half-domes clustered below the dome, the long flank of the nave and Giotto's campanile, with other towers of the city in front and hills beyond.

UNESCO describes the whole historic center, 505 hectares inside the line of the 14th-century walls, as the fruit of continuous creation over more than six centuries.

Florence Duomo as seen from Michelangelo hill
Photo: Petar Milošević, CC BY-SA 4.0, via Wikimedia Commons

Amazing facts

  • The dome has more than four million bricks.

    More than four million bricks were used to build the dome.

    Museo Galileo reports calculations that over four million bricks went into the dome, which weighs an estimated 37,000 tons.

  • Brunelleschi started out as a sculptor before he built the dome.

    Before he became an architect, Brunelleschi was a sculptor: in 1401 he entered a contest to make the second door of Florence's Baptistery and was judged equal with Lorenzo Ghiberti.

    Universalis notes that after the 1401 competition for the Baptistery's second door, in which he was judged equal with Lorenzo Ghiberti, Brunelleschi gave up sculpture; a stay in Rome, probably between 1404 and 1409, and the study of ancient monuments turned him toward architecture.

  • Leonardo da Vinci drew Brunelleschi's lifting machines.

    Brunelleschi left no drawings of his machines, but Leonardo da Vinci drew them in his notebooks.

    Brunelleschi left neither drawings nor descriptions of his machines; we know them from Taccola, Francesco di Giorgio, Bonaccorso Ghiberti, Giuliano da Sangallo and Leonardo da Vinci.

  • Lightning once hit the little tower on top of the dome.

    In the spring of 1601, lightning struck the lantern, and it was quickly repaired.

    Lightning damaged the lantern's structure in the spring of 1601; it was promptly restored.

Words to know

cathedral
the main church of an area led by a bishop
dome
a rounded roof shaped like half a ball
lantern
a small tower with windows on top of a dome
centring
a temporary frame that holds up an arch or dome while it is being built
herringbone
a zigzag pattern, like the bones of a fish
fresco
a painting made on wet plaster on a wall or ceiling

Discovery challenge

  1. Who built the cathedral's giant dome?

    Which architect designed the cathedral's dome?

    Which architect, appointed in 1420 to continue the work, built the dome without centring?

    • Filippo Brunelleschi
    • Michelangelo
    • Leonardo da Vinci
    Show the answer

    Filippo Brunelleschi

    Filippo Brunelleschi!

    Filippo Brunelleschi, from 1420 to 1436.

    Filippo Brunelleschi, appointed in 1420; the dome's general layout had been set by Arnolfo and Talenti.

  2. How many bricks are in the dome?

    About how many bricks went into the dome?

    How many bricks are calculated to have been used in the dome?

    • More than four million
    • About four hundred
    • Exactly forty
    Show the answer

    More than four million

    More than four million bricks!

    More than four million bricks.

    Over four million, for a dome estimated at 37,000 tons.

  3. What was missing under the dome while it was built?

    What did Brunelleschi build the dome without?

    What temporary support did the dome's construction do without?

    • A wooden frame to hold it up
    • Bricks
    • Workers
    Show the answer

    A wooden frame to hold it up

    A big wooden frame! He did not need one.

    A wooden frame, called centring, to hold the bricks up.

    Centring; herringbone brickwork made the dome self-supporting.

  4. In which country is Florence Cathedral?

    In which country is Florence Cathedral?

    In which country is the Historic Centre of Florence, inscribed in 1982?

    • Italy
    • Spain
    • France
    Show the answer

    Italy

    Italy!

    Italy, in the city of Florence.

    Italy: Florence, in Tuscany.

Nearby places

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For parents & teachers

What children will learn

  • Locate Florence Cathedral in Florence, Italy, and describe it as a cathedral begun in 1296 with a dome built from 1420 to 1436.
  • Explain why building a very large dome without a supporting frame was a problem, and how herringbone bricks and two shells helped.
  • Recognize that we know Brunelleschi's machines only from drawings made by other engineers.

Recommended ages: 4 to 17 · About 15 minutes

Talk about it

  • The cathedral was begun in 1296, but its dome was started only in 1420. Why might a building take so long?
  • Brunelleschi left no drawings of his machines. How do historians learn about things that were never written down?
  • Why might a lighter outer shell help protect the inner shell of a dome?

Try at home or in class

  • Build a small dome from sugar cubes or toy bricks, ring by ring, and see how far inward each ring can lean before it needs support.
  • Cut an orange in half and scoop it out: compare how strong the curved peel is when you press the top and when you press the side.

Key vocabulary: cathedral, dome, lantern, centring, herringbone, fresco

Where these facts come from

  1. Wikidata , Wikimedia Foundation (CC0 1.0)
  2. Historic Centre of Florence , UNESCO World Heritage Centre
  3. ARNOLFO DI CAMBIO (1245 env.-env. 1302) , Encyclopædia Universalis (French)
  4. BRUNELLESCHI FILIPPO (1377-1446) , Encyclopædia Universalis (French)
  5. The Dome of Santa Maria del Fiore , Museo Galileo, Institute and Museum of the History of Science
  6. Brunelleschi's Dome , Visit Tuscany (official tourism site of the Tuscany Region)
  7. Wikimedia Commons , Wikimedia Foundation (Per file (public domain, CC0, CC BY or CC BY-SA); see each media record)

Checked, not yet human-reviewed. Last updated November 1, 2026. Spotted a mistake? Tell us.

Picture credits
  • Photo: Petar Milošević, CC BY-SA 4.0, via Wikimedia Commons · source · license