Zanobi Machiavelli, 'Saint John the Baptist and Saint John the Evangelist', probably about 1470

These two panels, each depicting two saints standing on a tilted floor, are fragments of an altarpiece – a lost or unidentified central panel is likely to have shown the Virgin Mary and Christ Child. If that is the case, it’s likely that the tilted floor would have continued seamlessly across all the panels. But it’s also possible that a sculpture formed the centre of this ensemble. Either way, the orientation of the figures suggests that the panel showing Saints John the Baptist and John the Evangelist was originally on the left-hand side of the central image, with the panel showing Saints Mark and Augustine on the right.

Saint John the Baptist, identified by his camel-hair shirt and cross staff, makes direct eye contact with the viewer. He is joined by Saint John the Evangelist, one of the Twelve Apostles, who is using a quill to write in an open book, referring to his role as as one of the four authors of the Gospels. The eagle at his feet is his traditional symbol. A winged lion, the traditional symbol of Saint Mark, rests at the feet of the saint in the opposite panel. Mark, like John, was one of the Twelve Apostles. He holds a quill and his Gospel, which is closed, perhaps a comment on chronology: while the Gospel of Mark dates to the seventh decade AD, the Gospel of John was probably written around 100 AD. Mark is joined by Saint Augustine, the famous fourth-century theologian and Bishop of Hippo, himself a celebrated writer.

Nothing is known about the original layout and context of these panels, but the depiction of Saint Augustine suggests they were made for an Augustinian foundation. Scholars have speculated that the panels, which were acquired with the Lombardi-Baldi Collection in 1857, came from the Florentine church of S. Spirito, but there is little evidence for this claim. Another possibility is that they came from the Tuscan hilltop town of Montepulciano (where they were recorded in a private collection in the early nineteenth century). It has also been said that these two panels formed part of the same altarpiece as three other panels by Zanobi Machiavelli, but their shapes and sizes do not correspond.

On the back of Saint Mark and Saint Augustine there is a sketch of a portrait of a woman in profile, suggesting that the panel was originally meant for a different purpose or that it was used for study. No such portrait by the artist is known; he specialised in the production of altarpieces and devotional paintings.