The RETABLOS-TABERNÁCULO DE LA BAJA EDAD MEDIA EN LA CORONA DE CASTILLA [Tabernacle-Altarpieces from the Early Middle Ages in the Crown of Castille] research project: study, documentation and dissemination to be conducted by the University of Valladolid between 2018 and 2020, and funded by the Spanish Ministry of Economy, Industry and Competitiveness with a contribution from the European Regional Development Fund (ref. HAR2017-82949-P), aims to carry out an exhaustive analysis of a characteristic type of primitive altarpiece under the ancient Crown of Castille which consists of a baldaquin bearing a religious image and folding wings. Most of these tabernacle-altarpieces were removed once they fell out of fashion. About 30 of these are currently known to exist, though only five of them are more or less completely conserved.

The Museu Frederic Marès conserves what is without doubt the best example of this type, the Castildelgado (Burgos) tabernacle-altarpiece, as well as fragments of another two. Hence its key role in the project.