The building of the dome on Florence cathedral, by Filippo Brunelleschi, can be considered one of the Renaissance's main building enterprises. The highest expression of a new attitude, placing man and his abilities at the centre of the world and finding in classic antiquity the premises for cultural rebirth after the dark Middle Ages.
Renaissance society was based on completely different values to the medieval ones of chivalry and nobility. The new ideals were self-sufficiency, civic virtue, intelligence and almost unlimited trust in man's abilities.
Even though the Middle Ages weren't that far away and nor could they be considered the backward world depicted for so long, Renaissance men were aware they were different: in less than twenty years, starting from the building of the Brunelleschi Cupola, a small group of artists in just one city, Florence, brought about one of the most important revolutions in cultural history, and not just Italian.
The figure of Brunelleschi was in tune with this new world. He perfectly incarnated the figure of the Renaissance man, free, intelligent and trusting in the strength of his ideas. He was the son of a wealthy Florentine Notary and had been educated in a liberal manner; from boyhood onwards he'd shown interest in sculpture, mechanics and mathematics. To him we owe the study of the linear prospective which up until him, had already been used, but without precise rules of reference.
During the Renaissance period many artists felt the need to codify, to organise in treaties that huge knowledge heritage inherited from the past, so as to work with common reference points.
However, Brunelleschi, was not a scholar, nor even particularly well-educated. Vasari, 16th century author of the famous 'Lives of artists', tells us that he "reasoned with practical experience", and describes him as one of the first great technicians. He was also the first to introduce the figure of the architect as designer and single person completely responsible for a job: we mustn't forget that in the Middle Ages they put up complete cathedrals without a real project, just by trusting in the experience of all those working on the site. Works often went on for dozens, even hundreds of years making it impossible to forecast and control all the building stages.
So, in 1418 when Brunelleschi won the Cathedral Vestry Board competition, to complete the church of Santa Maria del Fiore, the work of Arnolfo di Cambio, by adding a vault, his project was so revolutionary as to seem inconceivable. The project, even if only at the start, invoked diffidence in those committed to it and malcontent among the workers.
The worker's strike is a famous episode: Brunelleschi fired them all on the spot and hired, in their place, ten 'Lombards'. The workers, jobless and hurt in their pride, went back and asked to be hired again. Brunelleschi satisfied them, but at a lower salary.
So, what did this Cupola have that was so amazing?
Brunelleschi had a brilliant idea: modeled on great Roman architecture, like the monumental Pantheon dome, that he'd studied and redesigned as a young man; he designed an octagonal, self-supporting dome, that didn't need a centre, built from different materials: stone down below where the curve was minimum, for greater resistance, and bricks above as they were lighter. Furthermore, the double pensa was formed by two spherical vaults placed one on top of the other, the internal one more than two meters thick and the external one just 80 centimeters.
These two parallel shells are connected by brick 'spurs' and have two different functions: the internal one is the real roofing while the external one, besides protecting from water, is there to thicken the dome profile, making it visible from afar.
But the most talented, really brilliant idea was how the bricks were fitted into each other, 'fishbone fashion', in the way that had been used in Tuscany prior to that, but never in similar circumstances. The secret of this colossal structure's balance lies in this knowledgeable jointing game, making the dome a complex, but perfect mechanical device.
Once finished, the dome was something extraordinary, never seen before.
Two years after the Cupola was finished in 1436, they added the crowning lantern in white marble, taking the total dome height from 91 to 114 metres, a really impressive height, and not just for that era.
Brunelleschi died in 1446 and managed to see his work practically finished, except for some decorations added afterwards. He was always aware that he had created a unique art and engineering masterpiece.
'It's as though the sky is envious' wrote Vasari,' as it keeps on shooting thunderbolts down at it, believing that its height has almost exceeded the height of air'.