Brunelleschi’s Dome of the Santa Maria del Fiore (Florence Cathedral) rises high above the city’s rooftops and is one of Florence‘s greatest landmarks. Originally the cathedral (duomo) had a temporary wooden dome built by the original architect, Arnolfo di Cambio, however when it came to designing a stone dome technical problems arose and the problem was swept under the carpet until later. By 1418 only the dome was still left uncompleted. The dome had been a constant embarrassment for the city, as no one quite knew how to build it.
In frustration, the “Arte del Lana” organised a competition to attract the great architectural minds of the country, to find a solution. 
So in 1419, the competition was held with the two main competitors being Lorenzo Ghiberti and Filippo Brunelleschi. In the end, the closely contended competition was won by sculptor, Brunelleschi whose design was inspired by the cupola of the Pantheon in Rome.
Brunelleschi’s design, a double-walled dome, was designed to rest on a drum rather than the roof itself, which meant there was no need for scaffolding. To create the dome, Brunelleschi created several models and invented special hoisting machines to lift the large stones.
In an act of jealousy, Ghiberti ridiculed Brunelleschi’s design and called it unfeasible. Brunelleschi, who had deliberately left his models incomplete to ensure his control over the project, left Florence in a huff and returned to Rome. Ghiberti was left holding the baby (so to speak) and soon realised it was beyond his expertise to complete.
In 1423 Brunelleschi returned to Florence to complete his dome and this time it was all under his terms and control. 
In 1436 the dome was finally completed and was declared the first “octagonal” dome in history to be built without a wooden supporting frame and the largest dome of the time. In fact even today it still remains the largest masonry dome in the world.
But all was not finished for Brunelleschi. Again his ability came into question over the crowning of the dome with a lantern. This resulted in yet another competition for which he also won, much to the displeasure of his two main competitors Antonio Ciaccheri and Lorenzo Ghiberti (he just never gives up!).
Brunelleschi’s design was for an octagonal lantern featuring eight radiating buttresses and eight high arched windows. Brunelleschi was never to see his design completed, as he died in 1446, a few months before work commenced.
It would take 25 years for the lantern to be completed following architectural alteration by various architects. In 1461 it eventually finished by his good friend Michelozzo. The finishing touches were made to the dome with a gilded copper ball and cross designed and created by Verrocchio added to the conical roof in 1469.