The Restoration of the Portico of Glory

Between 2006 and 2018, the Portico of Glory underwent a full study and complex restoration project, prompted by the cathedral's canonry and the Catedral de Santiago Foundation. It was made possible thanks to the patronage of the Barrié Foundation.The technical project was managed by the Catedral de Santiago Foundation and the Spanish Cultural Heritage Institute (Instituto del Patrimonio Cultural de España) and involved many different professional teams.

The restoration has enabled us to learn more about Master Mateo's work, solve various structural problems, and recover part of its polychrome, which had been hidden under a thick layer of grime.

The Portico of Glory was in a critical situation due to many different causes and over a long period of time. It was suffering constant material losses and was affected by complex physical and chemical issues degrading its materials.

For more than a decade, the Portico of Glory was subject to a process studying its state of preservation and was subsequently restored.The work was concluded in June 2018, and the result can now be viewed via organized visits to the Cathedral Museum.

The portico's restoration has provided an exceptional opportunity to deepen our knowledge about this masterpiece, and about Romanesque art in general, as well as the processes of deterioration that affect polychrome stone work.

Polychrome
During the restoration phase, it was possible to ascertain the existence of three complete layers of color, with other areas partially colored, which throughout the centuries had altered the portico's image.

First Layer of ColorThe oldest polychrome on the Portico of Glory dates from the construction undertaken by Master Mateo. However, this is not the only layer of color, and in its current form, the figures can be seen with various layers, from different periods.

Second Layer of ColorThe second layer identified has been dated to the early 16th century, coinciding with the construction of the Royal Hospital, following a visit from the Catholic Monarchs and the first restoration carried out on the portico's facade.

This layer is identified by its use of gold leaf, albeit of inferior quality to that used in the first layer, and the novel use of azurite as a replacement for lapis lazuli.It is also worth highlighting the use, in this second layer, of the technique of applied brocade, which helps us date the intervention to around the year 1520.

The main damage sustained by the portico was related to structural issues in this part of the cathedral, with filtrations of moisture, abrupt changes in temperature, and also damage to the monument caused by humans.

That is why the preventive measures that have been adopted, following the criteria of the experts who worked on the restoration, focus on:

Firstly, guaranteeing reliable management of the humidity and temperature conditions.

Secondly, taking action to control and limit the numbers of people accessing the area at any one time.