Triptych: the Crucifixion; the Redeemer with Angels; Saint Nicholas; Saint Gregory

This small altarpiece was made to open and close. Its two wings fold over the centre, and when they swing back they show Saint Nicholas on one side and a pope on the other, usually named as Saint Gregory, though Saint Clement has also been proposed. In the middle is the Crucifixion, and in the pointed gable above it Christ blesses between two angels. Opened out it is less than 80 centimetres wide, a size for a private chapel or a patron's own room rather than a church altar. The Museum of Fine Arts gives it to Duccio and his workshop and dates it to about 1311 to 1318. A triptych of the same build and decoration in the National Gallery in London, the Virgin and Child with Saints Dominic and Aurea, is thought to have come out of the same Siena workshop at the same time.