Stained glass window created in 1394-1395 by Leonardo di Simone, master glassmaker and Vallombrosan monk, to a cartoon by Agnolo Gaddi, one of the most important painters of the time.

This window is one of a group of four first commissioned in 1388, all similar in shape and iconology, adorning the mullioned openings of the third and fourth bays of the south and north aisles. In each work, the panels in stained glass conform with the elongated ogival forms of the openings and are divided along the vertical midline, with left and right sides arranged in three horizontal registers, for a total of six parts. Each part depicts a saint, standing within a tabernacle/temple niche. Despite the stylistic differences of the glass masters who created and installed the works, we can see the genius of Agnolo Gaddi in the highly accurate and fine design, and in the use, for the first time in Italian stained glass, of such complex tabernacles, already present in northern Europe and for these windows modelled on those of contemporary fresco painting.

Within a double border of gilded ribbons and flowers, identified by inscriptions in gilded plates, this window shows, at the top left, Saint Zenobius, first bishop of Florence and patron saint of the city, elderly and bearded, in the clothing of his role, with a clasp decorated with the Florentine lily. Next to him is Saint Reparata, young and with her hair tied back: she too shows the coat of arms of Florence, in this case on a sceptre, because according to legend, in 406 Zenobius called on her to come to the aid of Florence, besieged by the barbarian hordes of Radagaisus, at which time she miraculously assisted the Roman army of Stillicho in defending the city. Below are the twin figures of the Zenobius’ deacons, Eugene and Crescentius, co-protectors of the Diocese of Florence: both young, with tonsure and book, in red dalmatic and green cope. In the lowest register, on the right, is an unidentified saint, with tonsure and what seems to be Franciscan habit, cope and processional cross. At bottom left we can recognise Saint Catherine of Alexandria: young, beautiful, noble in appearance (reflecting her true lineage), holding the palm of martyrdom and a book, which alludes to wisdom and culture.