The altarpiece of Saint Dominic of Silos, now dismantled and dispersed in various collections, represents a valuable example of the transition towards the Renaissance in Spanish art. With a Gothic appearance and a profusion of gilding and decoration, the detailed central panel, dedicated to Saint Dominic, highlights the artist’s painterly skill and his deep knowledge of the oil painting technique, which is exceptional within his artistic circle, Figure 1.1
The painter is known as Bartolomé Bermejo, although his actual name was Bartolomé de Cardenas.2 Despite their common use in Italy at this time, he was the only fifteenthcentury Spanish painter to use a nickname. The reason for the use of ‘El Bermejo’, which means ‘red’ in old Spanish, is not certain, but the most plausible explanation is perhaps related to some physical trait. He was probably born in Córdoba, but there is no record of his activity in this city.3 The first documented work securely attributed to him, Saint Michael Triumphant over the Devil with the Donor Antonio Juan, currently in the collection of the National Gallery, London, was painted in Valencia in 1468.4
From the very beginning, the obvious northern influence in his technique has led his biographers to assume that he spent a period of apprenticeship in a city in Flanders, probably Bruges. Having returned to the Iberian peninsula, he is considered to have been an itinerant artist who worked in various places in Aragon, Valencia and Cataluña, wherever he was offered an attractive commission.
The altarpiece of Saint Dominic was originally located in Daroca, a prosperous, medium-sized town in the province of Zaragoza in north east Spain, which belonged to the kingdom of Aragon in the fifteenth century. It was a town with an economy based mainly on agriculture and livestock with a regional market, and was of some administrative importance.
The documentation relating to the commission of the altarpiece of Saint Dominic of Silos is well known and interesting, as it includes information not only on materials and artistic techniques, but also specific passages that relate directly to the artist’s personality. In the earliest surviving contract, dated 1474,5 some important issues are clarified:
To summarize, the contract is very explicit about the master’s personality; someone considered particularly gifted for the task entrusted to him but who must be controlled to ensure that he keeps his word.
Despite all these precautions, the contract was not fulfilled and the painter was finally excommunicated in July 1477, two and a half years after the date set for completion.7 In September of the same year, an addendum was added to the contract to the effect that another painter, Martin Bernat, undertook to complete Bermejo’s altarpiece “with him or without him”. Nevertheless, Bermejo’s mastery must have been so well considered by the commissioners that, despite excommunication and the manifest failure of the previous contract, they agreed to sign a second agreement with the painter in November. In this new document the collaboration with Martín Bernat was established, but Bermejo promised to complete the predella of the altarpiece and at least to draw and paint “by his own hand” the main images and all other “incarnaciones … [los] cuerpos nudo, y las caras” (flesh tones and heads) in the scenes. This second contract also established provisions for the control of expenditure, but was less restrictive than the first.
The Prado Museum’s collection includes two panels that belonged to the altarpiece of Saint Dominic in Daroca: the magnificent central panel dedicated to the saint, and one of the secondary scenes, painted some years later according to the documentation. The detailed study of both paintings makes a comparison possible that allows the degree of involvement of the master in the completion of the project to be determined.
Publications on technical aspects of works by Bartolomé Bermejo or other Aragonese painters of the fifteenth century are scarce. Some examples are Rebora, G., Rovera, G. and Bochiotti, G., Bartolomé Bermejo e il trittico di Acqui, L’Ancora Editrice, Acqui Terme (1987); and Rodriguez-López, A., Newman, R., Khandekar, N. and Gates, G., ‘Materials and techniques of a Spanish Renaissance panel painting’, Studies in Conservation 52 (2007) 81–100.
For biographical data and general information about the painter and his work, the 1997 monograph by Judith Berg has been used; Berg, J., Bartolomé de Cárdenas ‘El Bermejo’, pintor errante en la Corona de Aragón, International Scholar Publications, San Francisco (1997). English translation: Berg, J., Bartolomé de Cárdenas ‘El Bermejo’, itinerant painter in the Crown of Aragón, International Scholar Publications, San Francisco (1998).
His origin is based on the signature present on the frame of one of his works, La Piedad Desplá (Barcelona, Museu de la Catedral).
Berg, J., ‘Un nuevo documento sobre Bartolomé Bermejo’, Archivo Español de Arte XLI (1968) 61–62. Transcribed in Berg 1997, cited in note 2, 247–248.
First published in Serrano y Sanz, M., ‘Documentos relativos a la pintura de Aragón durante los siglos XIV y XV’, Revista de archivos, bibliotecas y museos 34 (1916) 462–492, esp. 482–485. Transcribed in Berg 1997, cited in note 2, 249–254.
Although there are some earlier examples, such as the altarpiece by Pere Johan for the ‘City House’ of Zaragoza in 1443 or the altarpiece by Tomas Giner for Saint John the Elder in Zaragoza in 1468, the reference to the oil technique in contracts is still uncommon in this period. See Bruquetas, R., Técnicas y materiales de la pintura española en los Siglos de Oro, Fundación de Apoyo a la Historia del Arte Hispánico, Madrid (2002) 322–323; Serra, A., ‘Métodos de producción de retablos en la pintura gótica hispánica: las fuentes documentales y su interpretación’, in La pintura europea sobre tabla. Siglos XV, XVI y XVII, Ministerio de Cultura, Madrid (2010) 13–19, esp. 17.
The Saint Dominic panel, which carries the main image of the altarpiece, depicts the patron saint facing the viewer directly, dressed and enthroned as a bishop. Included in the decoration of the throne, in small niches, are representations of the seven theological virtues.
Although the contract does not mention the participation of professionals other than the master and his administrator (the painter Juan de Bonilla), all the carpentry work and gilding of the altarpiece structure must have been carried out by other specialists. In the Iberian kingdoms at that time the organization of the various professions established strict differences in the responsibilities of each trade, as is clear from ordinances published in the late fifteenth and early sixteenth century.8
Regarding the wooden panel of Saint Dominic, in the first contract it is specified that the dimensions of a support that had already been assembled must be changed, with the aim of increasing its size. The X-ray study allowed the different phases in the evolution of the structure of the wooden support to be identified, up to its current state, Figure 2.
The panel, which is made of pine wood, at first consisted of five vertical planks9 assembled with four metal pins inserted in each join, as well as several small rectangular pieces of wood (3–8 mm wide and about 10 cm high) placed between the boards along the joins. The use of these intermediate wood fillets is not frequently found in Spanish panels; they have been described mainly in Valencian painting, although they are not unique to that area.10
While the back of the panel no longer has the original structure, the X-radiograph shows the former reinforcement system, which consisted of a crossed-beam structure called a ‘cross of Saint Andrew’ that was used frequently in the kingdom of Aragon in the fifteenth and sixteenth centuries. The beams, which form a cross or a star on the back, were attached with iron nails inserted from the front of the panel.11
As reflected in the contract, the dimensions were enlarged and the X-radiograph shows the extent of this enlargement. Two boards were added, one at the right side and the other to the top edge,12 attached directly without any intermediate fillets, and reinforced by metal pins similar to those used in the initial support. Finally, some horizontal and vertical battens were added over the joins. Two horizontal battens with dovetail profiles were added in a twentieth-century restoration, as were some canvas strips that are glued onto the back of the panel.
Once the boards were assembled, the surface of the wood was covered with fibres, which are visible in the X-radiograph and show no particular pattern of distribution.13 Over these fibres, a ground has been spread using a brush. It was applied in two layers, bound in animal glue. The lower, coarsely ground layer contains mainly anhydrite while the upper layer comprises gypsum with a smaller particle size; these two layers are analogous to the gesso grosso and gesso sottile described by Cennino Cennini.14 Grains of celestite (strontium sulphate), a very common impurity in Spanish gypsum ground layers, were found in both layers, Figure 3.15
The surface of the ground was covered and impregnated by a layer of animal glue, possibly applied with the intention of preventing excessive absorption of the binding medium used for the paint, as this could produce a decrease in the colour intensity and gloss. This aqueous sealing layer of irregular thickness (not observed in some samples), does not contain any pigment.
Over this grounded panel, Bermejo first traced the main lines of the scene and especially of the architecture, using a sharp instrument that incised thin lines into the white gypsum. These incisions are numerous in the architecture of the throne and the saint’s garments, but less abundant in the figure’s face, with only a few small lines around the eyes and hands. After making this first design, the artist corrected the path of the incised lines and added more detailed freehand elements, as well as modelling in the shadows using a brush with a fluid medium and black charcoal, as can be seen by infrared reflectography.
Despite the enlargement cited in the contract and confirmed by the X-radiograph, no major changes in the design of the scene were observed and no discontinuities can be seen in the drawn lines. The panel must have been enlarged before the proportions of the scene were fixed, and the elements were drawn directly over the entire surface of the grounded panel after it had been adjusted to its current size.
Due to the high proportion of the surface that is gilded rather than painted and its completely flat background, the panel depicting Saint Dominic exhibits a certain Medieval character, monumental and inexpressive. In this regard, it looks very different from other works Bermejo painted in the same period (e.g. the Acqui Terme Triptych or La Piedad Desplá) where he shows great skill in representing the textures of the coloured fabrics, as well as landscape backgrounds with aerial perspective. The gilded panel of Saint Dominic was, therefore, clearly designed in order to fulfil (in relative terms, as discussed below) the strict contract drawn up to the taste of his Aragonese commissioners, accustomed as they were to such modes of depiction.
Nevertheless, although the contract specified that the altarpiece must be painted in “gilded relief”, as was customary in Aragonese altarpieces, Bermejo did not apply this type of work. The textures and colours on the gold are made using oil glazes to simulate a fabric made of gold threads and embroidered with silks of various colours. The decoration of the cope, the border of the chasuble and the mitre are modelled with semi-transparent glazes and no other gilding technique (such as pastiglia, sgraffito or punching) has been used. In comparison with other contemporaneous artists working in the same area, the difference is obvious.16
Two different gilding techniques were used: water gilding on the background and oil gilding in the other areas. In both cases, a gold leaf of good quality was used, in which no other metal impurities were detected, and the thickness of the leaf is less than 1 µm.
In the burnished areas the gold has been laid on a homogeneous red bole layer with a thickness of 10–15 µm. In the oil gilded areas, i.e. those that were not to be burnished, the gold leaf is laid over a mordant layer composed of earth pigments and gypsum bound in linseed oil, with some added particles of a copper compound and red lead, probably to improve its drying properties.
The yellow of the gold acts as a mid-tone, with highlights achieved using fine touches of lead-tin yellow and shadows produced by applying a reddish-brown oil glaze (containing red lake and brown earth), the pigment content of which depends on the intensity that is required. The light, which enters from the left of the scene, leaves deep shadows in all the mouldings and arches, and in the folds of the garments. The decorative details of the garments were produced by applying small yellow and brown brushstrokes over the golden cloak using the tip of the brush, mimicking the effect of sgraffito.
The contract for the altarpiece of Saint Dominic of Silos does not yield much information concerning the materials to be used in the painting; it only requires that the painter should work in oil using good quality materials (“al olio, de colores finos et de adzur”). The specific material mentioned here is the blue pigment azurite, present in the decoration on the saint’s cloak.17
The tones used in the painting are basic colours and simple mixtures of the usual pigments for the period: lead white, leadtin yellow ‘type I’, verdigris, azurite, red and brown earths, vermilion, kermes red lake and charcoal black
In the few areas of the scene that are not gilded, no general priming layer over the ground has been found. Only under the white robe does there seem to be a thin white tempera layer, probably applied in order to hide the black lines of the underdrawing before painting.
Saint Dominic’s red chasuble shows a complex layer structure: over the white gypsum ground a thick semi-transparent red lake layer has been applied nuanced by a thin layer of this same lake mixed with lead white in a sketchy pattern of flowers. A final red glaze over this design was intended to provide a velvet-like finish, but this glaze has altered, becoming partially opaque, so that the chasuble now appears somewhat flat and without definition. The infrared reflectogram shows that underneath these layers a more complex decorative pattern was designed initially, but not finally executed.
A similar technique was used for the green textile: on a dark blue-green tone (a mixture of azurite and verdigris), the artist painted the design in a lighter green – made by adding lead white to the mixture – before covering the entire surface with a copper-containing glaze. In this case the desired effect has been achieved as the texture of the cloth is very realistic and has survived in perfect condition.
Bruquetas. R., ‘Los gremios, las ordenanzas, los obradores’, in La pintura europea sobre tabla. Siglos XV, XVI y XVII, Ministerio de Cultura, Madrid (2010) 20–31, esp. 26.
In Valencian painting, this type of assembly system has been reported by, among others, Calvo. See Calvo, A., La restauración de pintura sobre tabla: su aplicación a tres retablos góticos levantinos (Cinctorres, Castellón), Diputación de Castellón (1995) 93. Both the Prado Museum collection and the literature give examples found in Castilian circles, such as in the Apparition of Our Lady by Correa de Vivar (cat. P2832), all the panels that form the altar of St María la Mayor in Trujillo (Cáceres) by Fernando Gallego (Antelo, T., Gabaldón, A. and Vega, C., ‘Fernando Gallego en Trujillo: estudios físicos’, Bienes Culturales 8 (2008) 61–73, esp. 64) or the altarpiece attributed to the Master of Palanquinos in the Fine Arts Museum of Asturias: Hodge, S., Spring, M. and Marchant, R., ‘The construction and painting of a large Castilian retable: a study of techniques and workshop practices’, in Painting techniques, history, materials, and studio practice, ed. A. Roy and P. Smith, IIC, London (1998) 70–76, esp. 74. It has also been described in another painting by Bermejo or his workshop in the Hispanic Society of New York (Rodriguez-López 2007, cited in note 1).
For information about wooden panel construction techniques in Spanish painting see Veliz, Z., ‘Wooden panels and their preparation for painting in Spain from the Middle Ages to the seventeenth century’, in The structural conservation of panel paintings, ed. K. Dardes and A. Rothe, Getty Conservation Institute, Los Angeles (1998) 136–185; and Bruquetas 2002, cited in note 6, 223–256.
Santos, S., San Andrés, M., Balonedo, J.L., Conejo, O., Báez, M.I. and Rodriguez, A., ‘Contribution to the study of grounds for panel painting of the Spanish School in the fifteenth and sixteenth centuries’, in Painting techniques, history, materials, and studio practice, ed. A. Roy and P. Smith, IIC, London (1998) 115–119, esp. 118.
See works by other contemporary painters such as Martin Bernat himself, Tomas Giner and Miguel Ximenez.
In some contracts from the same period, the convenience of using an aqueous binder for obtaining a bright and resistant azurite blue paint is specified, such as in that for the altarpiece of Saint John the Elder of Zaragoza, the work of Thomas Giner in 1468 (Bruquetas 2002, cited in note 6, 323). This is not the case for the Saint Dominic panel and the blue layers bound with oil are much blackened.
The second panel represents a moment in the life of Saint Dominic of Silos when King Ferdinand I welcomed him to his court in Burgos after the saint had fled from the lands of Don Garcia of Najera, the king’s brother. As can be deduced from documentary information, this panel was painted some years after the main panel, with the intervention of Martin Bernat, Figure 4.
The support currently consists of five vertical boards buttjoined edge to edge, without any intermediate fillets of wood or metal pins.18 As in the main panel, despite later restoration of the support, the X-radiograph shows the traces of the original batten structure in the shape of a Saint Andrew’s cross.
An important and probably quite recent restoration can be traced in the X-radiograph. A horizontal cut that runs through all five boards can be seen 50 cm from the bottom edge. The reason for this cut is unknown, but it may relate to changes in its location; the size of the panel was drastically reduced to almost half and later reassembled. As well as a cradling system on the back, a join line and 13 metal pins, which are clearly regular and modern, can be seen.
The X-radiograph again shows the existence of a large number of thick fibres on the front of the panel, in this case mainly distributed over the joins. A sample of this material, accessible from the front, has allowed its identification as hemp. None of the samples of the ground layer that were taken was deep enough to determine whether there was an underlying layer of gesso grosso, except in the relief decoration where only gesso grosso, containing a small amount of celestite as an impurity, was found.
As in the central panel, the design of the scene was transferred by incising the lines with a sharp instrument on the white preparatory layer. A thicker stylus and deeper incisions were used than on the main panel and not only were the main lines defined but also other details such as the folds and shadows in the garments and other objects. The faces and hands were only outlined.
The incised lines were reinforced with a brush using a charcoal black bound in a fluid medium (possibly animal glue). Furthermore, the shadows, folds and other details were defined using numerous parallel lines; some of these features are particularly characteristic, such as the use of small crosshatched strokes in the deepest shadows, especially those on the foreheads of the figures under their hats, Figure 5.
The gilding is completely different to that described for the Saint Dominic panel. In this case, the artist responsible for the gilding undertook complex decorative work using an array of different techniques: pastiglia, punching and decorative painting, Figure 6.
In this panel, all the gold was laid over a red bole, a suitably soft base layer that allowed punching work as well as burnishing. The bole is slightly different to that on the main panel, less homogeneous with a greater proportion of gypsum and red iron oxide. The metal leaf has a similar thickness and composition, being pure gold.
Despite its excellent state of conservation, a thorough study of the materials provided no reason to doubt that the gilding was original. The red glaze over the golden royal cloak contains a kermes red lake, a material that was scarcely used after the fifteenth century.19 The craftsman responsible for the gilding work showed great skill, as it demonstrates a high level of complexity, especially on the king’s hat and some of the golden garments. Only the sky area has clearly been regilded, as two superimposed layers of gold with an intermediate adhesive layer (gypsum mixed with red pigments) between them were detected.
The paint samples show that a general light grey priming layer composed of oil, lead white, carbon black and large agglomerates of red lead was applied over the ground layer and drawing. Despite this layer, underdrawing is quite clearly visible through the paint layers.
The range of colours in this panel is narrower than on the Saint Dominic panel, reduced to shades of red and green with few other colours. The pigments identified were lead white, verdigris, vermilion, carbon black and kermes red lake; no blue pigment was used. The treatment of colour in this panel is completely different to that described for the main panel of the altarpiece. Although oil painting was used, the brushwork is considerably thicker and the modelling much less subtle. In some areas, the textural effects achieved by Bermejo in Saint Dominic are mimicked, but with far less ability. For instance, underneath the now plain green cloak of the king, a flowered pattern was painted, but the copper glaze layer has completely darkened so that it hides the textural effect.
Within the group of people that appear in the scene, some have been painted with more skill, particularly their faces and hands. The quality of painting in the principal characters is higher and some details – such as the beard, the small glints on the nails and the wrinkles at the corners of the eyes – recall the image of Saint Dominic, without achieving his quality and expressive strength. In contrast, the other faces are much simpler and more schematic, showing stereotypical traits.
In general terms, the quality of the painting is quite poor, strikingly unlike the gilding work. Furthermore, there are some details that reveal that not a great deal of care was taken when this painting was executed. For instance, the cap of one of the characters to the right apparently remains unfinished, with the ground layer and underdrawing fully exposed, just covered by a varnish layer, while the red band fastened with a jewel on the same hat appears perfectly finished. Although this might seem strange, it is possible that due to the eventful execution of this altarpiece it was simply left unfinished.
Width of the three central boards: 23.5–27.5 cm. Both side boards have been cut down from their original size. The back has been thinned and cradled; the original thickness cannot be determined
After the study of materials on both panels, some similarities can be found that are consistent with practices in local circles. However, although both painters employed an oil technique, there are considerable differences in the final results achieved.
Both the type of wood used for the supports and the reinforcement structures are similar in each panel and correspond to the usual practice in this region, with some local variations. Given that the supports were prepared at different times and possibly by different professionals, these disparities are not surprising.
However, important differences can be detected in the underdrawing, even though they have certain features in common. In both cases the design was first incised using a sharp instrument and later finished with fine and long brushstrokes. In the case of the panel of Saint Dominic, the incisions are limited to general outlines and the fluid underdrawing is loose, merely sketching the lines necessary to define shadows and folds. The panel depicting Ferdinand I shows a far greater abundance of drawing, both incised and painted, with more rigid and mechanical lines and the particular use of small crossed strokes in the darkest shadows.
The gilding in the two panels differs markedly; it is rather old-fashioned in the second panel studied, while Bermejo displayed great skill in the use of glazes on gold to simulate a relief decoration without using traditional techniques. The choice of materials and the type of mixtures used in the painted areas show similarities that reflect the availability of materials at that time and place. However, the way in which these materials have been used in the smaller panel demonstrates an obvious attempt to imitate the master’s technique, combining transparent and opaque layers, but with an inferior outcome.
Thus, within the strict limitations allowed by the contract, the much higher quality and remarkably innovative skills seen in the Saint Dominic panel are markedly different from Aragonese tradition. In contrast, the painting depicting the king Ferdinand I welcoming Saint Dominic fits perfectly into the local artistic environment, with gold relief decoration and a less refined painting technique.
Following this comparative study, the degree of participation of Bermejo in the second painting can be called into question. Following the detailed analysis of both works, it can be deduced that while the general design could have come from the hand of Master Bermejo, another artist carried out most of the work. In the second contract Bermejo undertook to “draw” all the scenes and finish “by his own hand” at least all the main characters and all the flesh tones, but he obviously did not fulfil this agreement. The faces and hands of the king and the saint show a better pictorial quality, but if they were indeed painted by the master he must have limited himself to these elements, although they still lack the same degree of refinement as seen in the central panel.
To summarize, the two panels that have been studied are good examples of the transition from the Medieval concept of art as an activity of craftsmen to a Renaissance way of thinking, and Bartolomé Bermejo probably best represents this period in Spain. Perhaps a strong-willed and highly self-confident man, he produced one of the Prado Museum’s masterpieces and moreover one of the masterpieces of Spanish fifteenth-century art.
Corresponding author: Dolores Gayo, Museo Nacional del Prado, Paseo del Prado, s/n, 28014 Madrid, Spain (dolores.gayo@ museodelprado.es).
Maite Jover and Laura Alba, Museo Nacional del Prado, Paseo del Prado, s/n, 28014 Madrid, Spain.