The image of Philip II on Horseback is inspired by the 16th-century concept of chivalry, transmitted via Flemish and Italian engravings of Roman emperors, and in particular by the equestrian portrait of Philip’s father, Charles V to be seen in the tapestry of The Capture of Tunis designed by Jan Cornelisz. Vermeyen between 1546 and 1554 (fig. 1). The face and torso in the portrait are copied from the portrait of Philip II in Armour painted by Titian in 1551.
It has been considered that Rubens painted Philip II on Horseback during his second stay in Madrid from 1628 to 1629. However, it is more likely that he painted it at a later date in Flanders as we know of at least three old copies of the painting that were executed there. In addition, the preparatory layer contains calcium carbonate, which was much more widely used in Flanders than in Spain. Furthermore, the painting is not documented in the Spanish royal collection prior to the 1686 inventory of the Alcázar in Madrid, suggesting that it was not there before 1636 or 1666, the dates of the previous inventories.
This posthumous portrait depicts the monarch in full armour and wearing a cloak and hat, mounted on a chestnut horse. In the background is a battle, probably referring to San Quintín (1557) when Philip’s troops defeated the French army. The winged Victory who crowns him with laurel supports this hypothesis.
In the last quarter of the 18th century the canvas was enlarged at the upper and lower edges, possibly in order to create a pair with the Equestrian Portrait of the Count Duke of Olivares by Velázquez, thus making them the same size until the present restoration.
The present restoration has allowed the Museum’s Technical Documentation and Analysis Laboratory to study the work and reach a series of conclusions on its state of preservation, the materials used by the artist and its technique.
In general, the research undertaken revealed the painting’s good state of preservation and determined that the type of preparation used is closer to that used by Rubens in Flanders to those that he deployed in Madrid. In addition, it was technically demonstrated that the additions are later ones made by a different painter, while finally, the original size of Rubens’s canvas could determined.
The preparation applied to the canvas of Philip II on Horseback is a light grey-brown colour. It contains calcium carbonate (natural chalk) to which small quantities of earth pigments were added to create a tinted tone, as well as a very small amount of white lead. Preparations of this type are commonly found in Flemish painting of the period.
In the x-ray it was possible to see that the overall state of the work is generally good. In addition, it revealed small corrections made during the process of execution: Rubens modified decorative elements of the horse, the fall of the King’s cloak and the face of the angel representing Victory (fig. 1). Such a direct manner of execution can perhaps be explained by the fact that Rubens was basing himself on pre-established iconographic models due to the posthumous nature of this portrait and perhaps in response to the patron’s requirements. These sources would have helped him when organising the composition. Furthermore, we know that the artist looked to the equestrian model of Charles V in Cornelisz. Vermeyen’s tapestry and that he copied the face from Philip II in Armour by Titian.
The dimensions of the canvas prior to restoration (314 x 228cm) did not correspond to the original size of Rubens’s painting (247 x 223cm), which had been enlarged in the 18th century, principally at the upper and lower edges. By analysing the area where the additional pieces of canvas joined the original one it was possible to appreciate different radiographic densities and different craquelure which clearly indicated the edges of the preparatory layer and the paint of Rubens’ original work, thus indicating the original dimensions of the painting (fig. 2).
In the micro-samples taken from the two added strips, the preparation is red and not grey-brown in colour and is basically made up of red earth and variable amounts of white lead. The proportion of white lead is greater in the upper strip than in the lower one, due to the fact that the painter/restorer wished to give the sky a lighter base tone. The materials used in the preparation of both added strips are the same, allowing for the conclusion that they were added at the same time (fig. 3).
Once it had been technically established that the additions to Philip II on Horseback were not original, it was decided to conceal them as they negatively affected a visual reading of the composition. It was decided that the most appropriate course of action would be to fold these added strips over a new stretcher of the size of Rubens’s original painting.
In order to do so, the areas where the original and additional canvases joined were cleaned, protecting the edge of Rubens’s original canvas with tapes (fig. 1). These joining zones were dampened on the reverse and the additional strips then folded over the new stretcher without affecting the original paint surface at any point. 1cm of non-original paint has been left on the front face but this is not visible to the viewer as it is behind the frame.
Although the additional, later strips at the top and bottom are no longer visible, the paint surface on them has been protected with tissue paper, attached with a thin layer of animal glue with the aim of protecting them and of guaranteeing their preservation and the reversibility of the procedure (fig. 2).
The next step was to clean the old varnish that covered the painting. It was a mastic varnish and could thus be removed with dissolvents. At this point it was possible to see the losses to the paint surface that had already been detected in the x-ray.
Old areas of filling-in (which were dark in tone) were brought up to the same colour as the new ones, which used the regattino technique in which fine parallel lines give areas of loss a sense of movement that simulates the effect produced by Rubens’ brushstrokes (fig. 3).
Having completed the re-touchings, the canvas was covered with a thin layer of varnish with sufficient penetration of the paint surface to maximise the colours’ effect of richness and moistness. Once the varnish had dried another thin layer of varnish was applied with a compressor and was then toned with a silk varnishing pad.
The restoration of the painting has allowed us to appreciate it as Rubens intended due to the fact that the procedure involved covering over later additions that detracted from the dramatic presence of the King in the composition. In addition, by removing old varnish and numerous areas of re-painting, the painting now has greater tonal coherence and has recovered the vibration of light and colour that characterise original works by this great Flemish painter (fig. 4).