The bronze panels on the baptismal font illustrate stories from the life of Saint John the Baptist, a sort of ‘sculpted biography,’ as narrated in the Gospels.
I. Announcement to Zechariah of John’s coming birth
The narrative begins with the panel in front of the altar, finished by Jacopo della Quercia in 1429. The scene shows the moment when the Archangel Gabriel announces to the elderly priest Zechariah that his barren wife Elizabeth will conceive a son (Luke 1:5-25).
II. The birth of John the Baptist
Turino di Sano and his son Giovanni di Turino were commissioned to provide two stories for the baptismal font, the Birth of John the Baptist and his Preaching, modeled from 1418 to 1420 but delivered only in 1427. In the Birth of John the Baptist, besides the scene where Elizabeth has given birth, we see on the left Zechariah writing John’s name on a tablet (Luke 1:57-58). Zechariah had been struck dumb because of his incredulity at the Angel’s announcement, and only recovered his power of speech after he confirmed that the name of his son was the one the angel had told him.
III. The Preaching of John the Baptist
The next panel shows John the Baptist Preaching. Matthew (3:1-12) explains that “In those days John the Baptist came, preaching in the Desert of Judea and saying, ‘Repent, for the kingdom of heaven is near.’… John's clothes were made of camel’s hair, and he had a leather belt around his waist… People went out to him from Jerusalem and all Judea and the whole region of the Jordan. Confessing their sins, they were baptized by him in the Jordan River.”
IV. The Baptism of Jesus Christ
The Baptism of Jesus (1427) is the work of Lorenzo Ghiberti, an artist who became famous after making the two sets of doors for the Baptistery of Florence. The panel reveals a pictorial sense and a grasp of perspective, rendered through the use of very shallow relief. Matthew (3:13-17) narrates that “as soon as Jesus was baptized, he went up out of the water. At that moment heaven was opened, and he saw the Spirit of God descending like a dove and lighting on him.”
V. The Capture of John the Baptist
The scene of the capture of John the Baptist is also the work of Lorenzo Ghiberti (1427). John the Baptist was imprisoned because in his preaching he had openly condemned the marriage of King Herod to Herodias, who had been his brother’s wife.
VI. Herod’s Banquet
The cycle concludes with the famous relief by Donatello (1427) of Herod’s Banquet, the most emotionally affecting scene of all for the drama of the subject and the panel’s formal qualities. The relief is evidence of the outstanding effects Donatello obtained with his invention of shallow relief: he manages to animate the figures in the foreground and to illustrate other episodes taking place on different planes, tying everything together with the spatial framework created by the perspective. This is the tragic conclusion of the story of John the Baptist: the “precursor” anticipates the Messiah also in his martyrdom. Its cause is the hatred borne by Herodias, the wife of Herod and formerly of Herod’s brother, who could not stand John’s criticism of this immoral union. She grasped the opportunity presented by her daughter Salome’s dancing, which so pleased Herod that he promised to fulfill any request the girl made: Herodias told her to ask for the head of John the Baptist, and the king, against his will, was forced to have the Baptist beheaded, and his head was brought to Salome and her mother on a platter.