Saint Matthew is shown writing his gospel; the angel beside him represents his divine inspiration. Saint Catherine of Alexandria wears the crown of a princess. Fragments of the wheel on which she was tortured lie at her feet. She was finally beheaded, hence the sword she carries. Saint John the Evangelist carries pen and ink at his belt. The eagle next to him symbolises the inspiration for his Book of Revelations, while the snake and chalice refer to his survival after having drunk poison. The damaged reverse shows Saint Jerome, a female martyr, Saint Gregory the Great and a kneeling donor in the cloak of a Knight of Malta. This painting once formed the left-hand shutter of an altarpiece, probably made for a church in Cologne, of which the central panel is now lost. The other shutter showing saints Mark, Barbara and Luke on the front and saints Ambrose, Cecilia and Augustine on the reverse, is in the Wallraf-Richartz Museum in Cologne. Both reverses include donors wearing the emblem of the Knights of Malta.