This painting in the National Gallery in London, is part of the Maesta Predella Panels. The double sided altarpiece, the "Maesta" made between 1308 - 1311 is recognised as Duccio's greatest work.
Read more about the Maesta of Duccio on Wikipedia

The National Gallery houses the national collection of Western European painting from the 13th to 19th century.

This painting by Duccio in the National Gallery in London, is part of the Maesta Predella Panels.

This painting in the National Gallery in London, is part of the Maesta Predella Panels.