Saint Francis before the Sultan

Saint Francis of Assisi, eager to defend his faith through martyrdom, went to Syria to preach to its Muslim population around 1219, at the time of the Fifth Crusade (one of a series of invasions of Muslim countries by Christian armies attempting to recapture the Holy Land). He and his companion, Brother Illuminatio, were captured and taken before al Malik al Kamil, Sultan of Egypt and Syria, who was defending Damietta from the Christian forces. According to the Legenda Maior, Francis's official biography, he attempted to convert the Sultan to Christianity by offering to go through fire for this faith. The Sultan politely declined his offer and sent him back to the Christian army.

The Sultan, in a white turban and with fair hair, sits on a raised throne under a green and pink arcade. In the centre, Francis makes the sign of the Cross and prepares to step into the curling flames. Brother Illuminatio looks on, along with various members of the Sultan's court, some in turbans (perhaps the imams who had refused the saint's challenge). Through an arched doorway at the back of the building we can see a barren wilderness with rocky hills, one topped with towers.

This painting comes from the San Sepolcro Altarpiece, a large and complex polyptych painted by Sassetta for the Franciscans of Borgo San Sepolcro. The back showed Saint Francis in Glory (Berenson Collection, Villa I Tatti, Settignano) surrounded by eight episodes from his life, seven of which are in our collection. This panel was in the top row, on the right-hand side, next to The Wolf of Gubbio. The landscape in this panel continued from that painting: the two stories were together treated as examples of Francis's preaching and peacemaking by the influential Franciscan writer Bartolomeo da Pisa, whose writings inform various aspects of the altarpiece's iconography.

Although Francis did not actually walk through the flames, the scripta, the written instructions which the friars gave the artist, told Sassetta to show 'when he [Francis] appeared before the Sultan and entered the fire'. As elsewhere in the San Sepolcro Altarpiece, the artist has used large amounts of gold and silver, some of which is badly worn: the picture would originally have been brighter and shinier. The swirling flames were originally painted in vermillion pigment over gold; the exposed gilding was stippled with a metal punch to give a sense of the movement of a flickering fire. The Sultan's tunic was originally white over gold - the pattern was scratched into the white pigment to reveal the gold beneath (a technique known as sgraffito) - while the costume of the figure with a sword on the right was silver with a red lake glaze. His sword and belt are blue over silver, which has darkened, as has the robe of the standing figure with the pink turban.

Credit: Bought with contributions from the Art Fund, Benjamin Guinness and Lord Bearsted, 1934