By 1296, Arnolfo di Cambio’s project to enlarge the Santa Reparata Cathedral was at its completion point; the first stone of the new cathedral was laid and its name was changed to Santa Maria del Fiore, a combination of the Virgin Mary and the symbol of Florence. In the 14th century, Francesco Talenti expanded Arnolfo’s original project, adding the apse (1380-1420), with the tribunes reaching as far as the dome’s drum.
The dimensions of this new cathedral, planned and built by Arnolfo, were undoubtedly in line with the dense medieval framework of the “Matilda” area, a city layout composed of low buildings, towers and narrow winding roads; however, the new structure was also linked to the new city walls. For the first time in Florence, a building was erected in perfect scale with the city, a structure capable of bringing together elements that previous frameworks did not unite cohesively. Construction for the new cathedral (meant to accommodate 30,000 people) lasted about a century, requiring a crew of hundreds of people for its edification. And all this without considering the cupola itself, designed and built by Filippo Brunelleschi.
The Florence Cathedral’s size (approximately 153 m in length; 38 m wide; transept, approximately 90 m wide) makes it the fourth largest church in the world after Saint Peter’s Basilica in Rome, Saint Paul’s Cathedral in London and the Duomo in Milan. Financed by Florence’s Arti Maggiori, its imposing size caused the demolition of a large number of surrounding buildings. In the 14th century, Anrnolfo’s original plans underwent a number of interventions aimed at enhancing the baptistery and cathedral complex and defining the surrounding empty spaces.
Despite boasting a history of complex interventions, the cathedral’s architectural base is faithful to Arnolfo’s original plans. Inserting longitudinal naves on a wide central body (dominated by the cupola) was a brave decision at the time, though it was not an entirely new concept, as Roman and Gothic architecture in Tuscany vaunted the same layout (such as Siena’s cathedral). The idea supposedly derived from Arnolfo himself and was later enhanced by Brunelleschi. The luminous and proportionate internal spaces were a sort of meeting place for the community, the main square for the outside space surrounding the cathedral and baptistery.
In today’s church, the much-studied proportions indicate the relations at the base of its construction; the square and octagon are the two dominating shapes. “The nave, work of Francesco Talenti, which changed the proportions of Arnolfo’s original drawing by giving more breath to the bays and making them perfectly square in shape, reinforces the cubic sense of space already expressed by the extraordinary width of the arches and by the imposing gallery, which runs through the vaults and stops any impression of verticality” (L. Gori Montanelli).
While the total length of the church is about 3 times longer than that of Santa Croce, the width of the longitudinal part (set by Arnolfo) is more or less the same, though the spaces between the pillars are wider. The frame itself is an uncommon size for 13th-century churches, yet the overall complex vaunts perfectly harmonious proportions. Due to the church's covered vaults, the overall unification of the space had been previously defined differently than that of Santa Croce.