The dome of Santa Maria del Fiore Cathedral, the Duomo of Florence, is the famous construction designed by Filippo Brunelleschi, at the time the largest dome in the world and still today the largest in masonry ever built, with a diameter of 45, 5 meters.
When, in 1420, Filippo Brunelleschi was appointed to continue the work already done, the general layout of the cupola and its design were already in place, due to the work done by his predecessors (Arnolfo and Talenti). The internal diameter was near the maximum limit of any type of bricked dome constructed at the time.
Instead of looking for solutions talready used in precedence, Brunelleschi invented a technique based on ancient Rome’s ‘way of bricklaying’, as well as medieval and oriental building. The possibility of building such a large cupola was based on this innovative technique that avoids any kind of discontinuity of the masonry and allows for an easier construction of the wooden supports needed to sustain this kind of structure.
The shape of the bricks, which are called ‘herringbone bricks’, allowed Brunelleschi to construct the wall listels, each one having a type of vertical hook for the successive hooks. In this way the dome is in fact a self-supporting and expansive structure.
The result is surprisingly modern. The cupola consists of two ogival-shaped caps connected to each other; the lighter exterior cupola protects the inner one from the elements, while the two work together thanks to the powerful connecting ribs.
Above the dome stands the lanterna with a cone-shaped cover, also designed by Brunelleschi and built after his death(1446), and the gilded copper ball with the cross, a of Andrea del Verrocchio, placed here in 1466.
Inside, the cupola is decorated with an extraordinary cycle of frescoes depicting the Last Judgement, painted between 1572 and 1579 by Giorgio Vasari and Federico Zuccari.