The Cathedral’s 44 windows constitute the most extensive stained glass program in 14th and 15th-century Italy. The windows depict Old and New Testament saints (in the nave and transepts), and scenes from the life of Christ and Mary (in the circular windows of the drum). The list of artists includes the greatest Florentines of the early Renaissance: Donatello, Ghiberti, Paolo Uccello and Andrea del Castagno. From the crossing, under the dome, one has a sweeping view, and the iconological purpose of the window program becomes apparent: to evoke the spiritual light in Christ, Mary and the saints which enlightens believers. The New Testament claims, in fact, that in Christ was life, “and that life was the light of men, a light that shines in the dark, a light that darkness could not overpower” (John 1,4).

Our architectural and religious journey culminates in the area under the dome, defined by the choir enclosure and high altar. The enclosure – octagonal in shape, like the dome above it – reiterates the symbolism of the Baptistery. The surface occupied by the enclosure is, in fact, almost identical with that inside the Baptistery, thus recreating Florence’s oldest sacred space here beneath the Renaissance cupola. Our impression of an infinite dilation of the Baptistery would have been reinforced by the mosaic decoration which, according to old sources, Brunelleschi wanted applied to the dome interior.

As finally executed by Giorgio Vasari and Federico Zuccari between 1572 and 1579, the decoration of the dome is not in mosaic but painted. The iconographic theme however is the same as in the Baptistery: the Last Judgement. 3,600 meters of painted surface illustrate traditional Catholic belief in a Heaven and Hell which human beings “merit” on the basis of virtues or vices cultivated during their life on earth, and after a final “judgement” at the end of the “available time” of history. In the center, above the high altar, the Risen Lord appears amid angels bearing the instruments of his Passion. This dominant image of the dome, by Federico Zuccari, was meant to be seen in relation to a sculptural group carved by Baccio Bandinelli 20 years earlier for the high altar: a monumental dead Christ on the altar, and a Figure of God the Father blessing. These statues, removed in 1842, were the first part of a unified message, the full sense of which was revealed in the dome. On the altar, believers saw the dead Christ, but, lifting their eyes, beheld the same Lord in glory.

Plan of the Dome Frescoes

A – The Elders of Revelation 4.
B – Angelic Choirs with the Instruments of Christ’s Passion.
C – Christ, Mary and the Saints.
D – Virtues, Beatitudes and Gifts of the Holy Spirit.
E – Vices and Hell.
F – Windows in the drum:
       1) Donatello, Coronation of Mary.
       2) Paolo Uccello, Resurrection of Christ.
       3) Andrea del Castagno, Deposition.
       4) Paolo Uccello, Nativity of Christ.
       5) Paolo Uccello, Annunciation (destroyed).
       6) Lorenzo Ghiberti, Presentation in the Temple.
       7) Lorenzo Ghiberti, Agony in the Garden.
       8) Lorenzo Ghiberti, Ascension.

The frescos were entirely restored between 1978 and 1994. Of the choir enclosure, which originally had a superstructure of columns, architraves and balusters, today only the sustaining wall remains, with reliefs, by Bandinelli and his assistants, depicting Old Testament prophets. And the altar we see today, nearer us than the 16th-century altar, was put in place in 1973 in conformity with the Second Vatican Council’s liturgical reforms.

Beyond the altar stands the Bishop’s Chair, symbolizing the teaching authority of Christ, and which – from its Greek name, “cathedra” – gives the title “cathedral” to any church in which a bishop normally presides. The figure of Christ on the monumental crucifix behind the Bishop’s Chair is by Benedetto da Majano, c. 1495-1497.

Finally, behind the choir enclosure, bronze doors by Luca delIa Robbia open onto the north sacristy, called the “Mass sacristy”: a chamber adorned with inlaid wood panels by Florentine masters of the l5th century, fully restored after the 1966 flood. These artists’ use of linear perspective (invented by Brunelleschi in the early 1400s in Santa Maria del Fiore) is impressive. In the sacristy, where vestments, books and other objects needed for Mass are kept, the inlays give the illusion of cabinets half-open, with the objects visible on the shelves. Over the door of the sacristy is a Resurrection of Christ by Luca delIa Robbia, in glazed terra cotta, and – above this, where now we see the 19th-century organ-facing – Luca della Robbia’s Singing Gallery was once situated. In the corresponding position over the south sacristy door was Donatello’s Singing Gallery. Both works are now in the Museum of the Opera del Duomo.