The oldest building on the Square is the Baptistery of Saint John, for centuries thought to be a pagan temple “converted” to Christian use. In effect, toward the end of classical antiquity – in the 5th or early 6th century – a first baptistery was erected here, in front of the then cathedral, Santa Reparata, in a spatial relationship similar to what we see today. That primitive baptistery must have been similar to the present one in its form too: an octagon, symbolizing the “octava dies” or “eighth day” : the time of the Risen Christ, beyond our earthly time measured in units of seven days. Such symbolism was held to be relevant to Baptism, the sacrament of initiation into the Christian faith, whereby believers pass from death in sin to new life in Christ, an infinite “eighth day”. The octagonal form thus alludes to Christians’ hope for a resurrection of the dead, and must have had great expressive power when the building was still surrounded by a cemetery.

Beginning in the mid-11th century, the Baptistery was reconstructed on the larger scale we see today, and embellished with costly marble, much of it from ancient structures. This was a period of economic and political achievement, in which Florence became, first, the seat of Imperial government in Tuscany, and then broke free from the Holy Roman Empire. In the 12th and 13th centuries, the new Baptistery was further enlarged with a monumental dome and the rectangular apse (“scarsella”) on the west side, becoming an object of civic pride: Dante calls it his “lovely Saint John’s”. And from the 14th to the 16th century, the exterior sculptural decoration for which the Baptistery is famous was put in place: three sets of bronze doors and the bronze and marble statuary above them. These works illustrate Bible stories which the believer is invited to ponder if he would live his faith to the full. The oldest doors are those today on the south side, depicting the life of John the Baptist, titular saint of the Baptistery and the city’s patron: they were fashioned by Andrea Pisano in the 1330s. Next are the north doors executed by Lorenzo Ghiberti between 1402-1425: these depict the life of Christ. And last, to the east, are the “Gates of Paradise” (as Michelangelo called them), with scenes from the Old Testament, modeled and cast by Ghiberti between 1425-1450 (now replaced with copies).

Door by Andrea Pisano (south door)
with scenes of the life of Saint John the Baptist.

1) The angel announces to Zechariah
2) Zechariah is struck mute
3) Visitation
4) Birth of the Baptist
5) Zechariah writes the boy’s name
6) Saint John as a boy in the desert
7) Preaches to the Pharisees
8) Announces Christ
9) Baptism of his disciples
10) Baptism of Jesus
11) Saint John reprimands Herod
12) Incarceration of Saint John
13) The disciples visit John
14) The disciples visit Jesus
15) Salome’s dance
16) Decapitation of Saint John the Baptist
17) Presentation of the head to Herod
18) Salome takes the head to Herodias
19) Transport of the body of John
20) Burial
A) Hope
B)  Faith
C) Charity
D) Humility
E) Fortitude
F) Temperance
G) Justice
H)  Prudence.

First door by Lorenzo Ghiberti (north door)
with scenes from the New Testament.

1) Annunciation
2) Nativity
3) Adoration of the Magi
4) Dispute with the doctors
5) Baptism of Christ
6) The Temptation
7) Chasing the merchants from the temple
8) Jesus walks on water and saves Peter
9) Transfiguration
10) Resurrection of Lazarus
11) Entry of Jesus into Jerusalem
12) Last Supper
13) Agony in the Garden
14) Christ captured
15) The Flagellation
16) Jesus before Pilate
17) Ascent to Calvary
18) Crucifixion
19) Resurrection
20) Pentecost
A) Saint John Evangelist
B) Saint Matthew
C) Saint Luke
D) Saint Mark
E) Saint Ambrose
F) Saint Jerome
G) Saint Gregory
H) Saint Augustine.

“Gates of Paradise” by Lorenzo Ghiberti (east door)
with scenes from the Old Testament.

Stories of:
1) Adam and Eve
2) Cain and Abel
3) Noah
4) Abraham
5) Isaac and his sons, Esau and Jacob
6) Joseph
7) Moses
8) Joshua
9) David
10) Solomon and the Queen of Sheba.