Attributed to Pietro Lorenzetti and his workshop, this polyptych is like a miniature version of a large altarpiece. In the centre are depictions of the Crucifixion and the enthroned Virgin and Child with a kneeling deacon. The left-hand side recounts the calling and martyrdom of St Matthew, while the sections on the right show St John on the island of Patmos and his ascension to heaven. Parts of the latter scene reveal the influence of Giotto’s fresco in Santa Croce in Florence. This wittily devised pictorial narrative is crowned by a row of saints and the Annunciation.