The Basilica di Santa Maria del Fiore (English, "Basilica of Saint Mary of the Flower") is the main church of Florence, Italy. The cathedral of Florence is built as a basilica, having a wide central nave of four square bays, with an aisle on either side. The chancel and transepts are of identical polygonal plan, separated by two smaller polygonal chapels. The whole plan forms a Latin cross. The nave and aisles are separated by wide pointed Gothic arches resting on composite piers. The dimensions of the building are enormous: length 153 metres (502 ft), width 38 metres (124 ft), width at the crossing 90 metres (295 ft). The height of the arches in the aisles is 23 metres (75 ft). The height of the dome is 114.5 m. Il Duomo di Firenze, as it is ordinarily called, was begun in 1296 in the Gothic style to the design of Arnolfo di Cambio and completed structurally in 1436 with the dome engineered by Filippo Brunelleschi. The exterior of the basilica is faced with polychrome marble panels in various shades of green and pink bordered by white and has an elaborate 19th-century Gothic Revival façade by Emilio De Fabris. The cathedral complex, located in Piazza del Duomo, includes the Baptistery and Giotto's Campanile. The three buildings are part of the UNESCO World Heritage Site covering the historic centre of Florence and are a major attraction to tourists visiting the region of Tuscany. The basilica is one of Italy's largest churches, and until development of new structural materials in the modern era, the dome was the largest in the world. It remains the largest brick dome ever constructed. The cathedral is the mother church of the Roman Catholic Archdiocese of Florence, whose archbishop is currently Giuseppe Betori. Santa Maria del Fiore was built on the site of an earlier cathedral dedicated to Saint Reparata. The ancient structure, founded in the early 5th century and having undergone many repairs, was crumbling with age, as attested in the 14th century Nuova Cronica of Giovanni Villani, and was no longer large enough to serve the growing population of the city. Other major Tuscan cities had undertaken ambitious reconstructions of their cathedrals during the Late Medieval period, as seen at Pisa and particularly Siena where the enormous proposed extensions were never completed. The new church was designed by Arnolfo di Cambio and approved by city council in 1294. Arnolfo di Cambio was also architect of the church of Santa Croce and the Palazzo Vecchio. He designed three wide naves ending under the octagonal dome, with the middle nave covering the area of Santa Reparata. The first stone was laid on September 9, 1296, by Cardinal Valeriana, the first papal legate ever sent to Florence. The building of this vast project was to last 140 years, the collective efforts of several generations; Arnolfo's plan for the eastern end, although maintained in concept, was greatly expanded in size. After Arnolfo died in 1302, work on the cathedral slowed for the following thirty years. When the relics of Saint Zenobius were discovered in 1330 in Santa Reparata, the project obtained new impetus. In 1331, the Arte della Lana, the guild of wool merchants, took over exclusive patronage for the construction of the cathedral and in 1334 appointed Giotto to oversee the work. Assisted by Andrea Pisano, Giotto continued di Cambio's design. His major accomplishment was the building of the campanile. When Giotto died in 1337, Andrea Pisano continued the building until work was again halted due to the Black Death in 1348. In 1349, work resumed on the cathedral under a series of architects, commencing with Francesco Talenti, who finished the campanile and enlarged the overall project to include the apse and the side chapels. In 1359 Talenti was succeeded by Giovanni di Lapo Ghini (1360–1369) who divided the center nave in four square bays. Other architects were Alberto Arnoldi, Giovanni d'Ambrogio, Neri di Fioravante and Andrea Orcagna. By 1375, the old church Santa Reparata was pulled down. The nave was finished by 1380, and by 1418, only the dome remained incomplete. On 18 August 1418, the Arte della Lana announced a structural design competition for erecting Neri's dome. The two main competitors were two master goldsmiths, Lorenzo Ghiberti and Filippo Brunelleschi, the latter of whom was supported by Cosimo de Medici. Ghiberti had been the winner of a competition for a pair of bronze doors for the Baptistery in 1401 and lifelong competition between the two remained acute. Brunelleschi won and received the commission. Ghiberti, appointed coadjutator, was drawing a salary equal to Brunelleschi's and, though neither was awarded the announced prize of 200 florins, would potentially earn equal credit, while spending most of his time on other projects. When Brunelleschi became ill, or feigned illness, the project was briefly in the hands of Ghiberti. But Ghiberti soon had to admit that the whole project was beyond him. In 1423 Brunelleschi was back in charge and took over sole responsibility. Work started on the dome in 1420 and was completed in 1436. The cathedral was consecrated by Pope Eugene IV on March 25, 1436, (the first day of the year according to the Florentine calendar). It was the first 'octagonal' dome in history to be built without a temporary wooden supporting frame: the Roman Pantheon, a circular dome, was built in 117–128 AD with support structures. It was one of the most impressive projects of the Renaissance. During the consecration service in 1436, Guillaume Dufay's similarly unique motet Nuper rosarum flores was performed. The structure of this motet was strongly influenced by the structure of the dome. The building of such a masonry dome posed many technical problems. Brunelleschi looked to the great dome of the Pantheon in Rome for solutions. The dome of the Pantheon is a single shell of concrete, the formula for which had long since been forgotten. A wooden form had held the Pantheon dome aloft while its concrete set, but for the height and breadth of the dome designed by Neri, starting 52 metres (171 ft) above the floor and spanning 44 metres (144 ft), there was not enough timber in Tuscany to build the scaffolding and forms. Brunelleschi chose to follow such design and employed a double shell, made of sandstone and marble. Brunelleschi would have to build the dome out of bricks, due to its light weight compared to stone and easier to form, and with nothing under it during construction. To illustrate his proposed structural plan, he constructed a wooden and brick model with the help of Donatello and Nanni di Banco, a model which is still displayed in the Museo dell'Opera del Duomo. The model served as a guide for the craftsmen, but was intentionally incomplete, so as to ensure Brunelleschi's control over the construction. Brunelleschi's solutions were ingenious. The spreading problem was solved by a set of four internal horizontal stone and iron chains, serving as barrel hoops, embedded within the inner dome: one each at the top and bottom, with the remaining two evenly spaced between them. A fifth chain, made of wood, was placed between the first and second of the stone chains. Since the dome was octagonal rather than round, a simple chain, squeezing the dome like a barrel hoop, would have put all its pressure on the eight corners of the dome. The chains needed to be rigid octagons, stiff enough to hold their shape, so as not to deform the dome as they held it together. The original facade, designed by Arnolfo di Cambio and usually attributed to Giotto, was actually begun twenty years after Giotto's death. A mid-15th-century pen-and-ink drawing of this so-called Giotto's façade is visible in the Codex Rustici, and in the drawing of Bernardino Poccetti in 1587, both on display in the Museum of the Opera del Duomo. This façade was the collective work of several artists, among them Andrea Orcagna and Taddeo Gaddi. This original façade was completed in only its lower portion and then left unfinished. It was dismantled in 1587-1588 by the Medici court architect Bernardo Buontalenti, ordered by Grand Duke Francesco I de' Medici, as it appeared totally outmoded in Renaissance times. Some of the original sculptures are on display in the Museum Opera del Duomo, behind the cathedral. Others are now in the Berlin Museum and in the Louvre. The competition for a new façade turned into a huge corruption scandal. The wooden model for the façade of Buontalenti is on display in the Museum Opera del Duomo. A few new designs had been proposed in later years, but the models (of Giovanni Antonio Dosio, Giovanni de' Medici with Alessandro Pieroni and Giambologna) were not accepted. The façade was then left bare until the 19th century. The decoration of the exterior of the cathedral, begun in the 14th century, was not completed until 1887, when the polychrome marble façade was completed to the design of Emilio De Fabris. The floor of the church was relaid in marble tiles in the 16th century.