It was found in the sanctuary of the church of Sant Jaume de Frontanyà. Originally, this altarpiece was made up of two large sections of which only the bottom part has survived. In the top section, there were probably descriptive scenes of the life and martyrdom of the Apostle, while the bottom one depicts scenes showing the handing-over of the relics and miracles of the Saint. This magnificent work was probably destroyed at the end of the 19th century; in 1909, a few fragments came to the museum, which, along with those arriving in 1918, allowed the reconstruction of this part of the altarpiece. It is a Catalan work in the Gothic linear style created using the technique of tempera on silver varnish.