If the war machines were a fanciful promise, the paintings and drawings that Leonardo brought to Milan were a marvellous reality, and it was these that came to fruition at the Lombard court.
He had barely had time to organize his new house when he was offered a contract, in 1483, to paint a large altarpiece for the chapel of the Immaculate Conception in the church of San Francesco Grande, in the centre of Milan. The Milanese confraternity of San Francesco had been set up in 1479, and the chapel was completed the following year. The Franciscans enjoyed a prominent position in Milan and the Marian cult was celebrated with great devotion in this confraternity, all the more so because a Milanese theologian (Bernardino de’ Busti) had perfected the office for the Feast of the Immaculate Conception that was approved by Sixtus IV in 1480. The decoration of the chapel was therefore a matter of considerable importance, and the panel that Leonardo was commissioned to paint would be inserted in a large wooden structure resembling a small temple, which had been carved in 1482 with relief motifs and decorated compartments. Leonardo was asked not only to produce the central panel but also to gild and paint the carved reliefs.
The contract that was drawn up with the members of the confraternity was very detailed, especially with regard to the materials to be used, and, as was customary in the Middle Ages and the Renaissance, these materials defined the value and importance of the painting. Chief among them was the gold leaf, which had to be purchased from the confraternity itself, and the precious ultramarine blue, the crushed lapis lazuli that represented the most prized element in a celebratory painting. The contract also stipulated the type of medium to be used in painting the Virgin: oil. Oil had to be used to paint the mountains as well, a detail that tells us that the theme and the type of painting had been carefully studied by the monks before its execution. It also reveals that, in the late fifteenth century, oil painting was recognized as a much more precious and refined form of art than painting in tempera, which by then was regarded as obsolete, in northern Italy above all.
Rumours of the artist’s legendary slowness and his difficulty in finishing works must have reached the Franciscan monks, since the contract was drawn up with Leonardo and two other Milanese artists, Ambrogio and Evangelista de Predis. The presence of no less than two others who would work alongside Leonardo must have offered a good guarantee for the work’s success, or at least for its completion. Leonardo accepted the collaboration, aware that the work would decide his future in Milan, and indeed he was already overwhelmed by so many new interests and speculations that the presence of these two painters would have lessened the burden of work and ensured that he would have time to dedicate himself to other matters. The panel was completed, miraculously and with astounding results, within the space of a few years, certainly by 1486, but fate decreed that patrons would not be satisfied with Leonardo, even in Milan. The painting was so beautiful that the price of 200 ducats agreed before its realization was deemed completely inadequate. The extraordinary success of the painting prompted Leonardo to demand an additional payment, which the confraternity refused to pay in full. Indeed, they only agreed to pay an extra 25 ducats. But then a purchaser, we do not know who, offered to buy the work for an additional 100 ducats – half as much again as the original contractual price.
This dispute is indicative of the changing relationship between artists and their patrons during the Renaissance, because that ‘additional fee’ referred to, and claimed payment for, something that gave value to the work over and above its craftsmanship and the valuable materials used (gold and lapis lazuli): the talent of the artist, which was becoming emancipated from the purely mechanical aspects of the work. At the same time, the dispute confirms that Leonardo’s position in Milan was much more than that of an artisan, be it one of the highest level. Confronting a patron with a demand of this nature would have been unthinkable if Leonardo had not been able to rely on the support of his protector, Ludovico Sforza, whom some scholars have identified as the anonymous collector who offered to buy the painting for so much more than the original price. Ludovico was aware of the value of the painting and of its political use, and he wanted to buy it as a gift, perhaps for his nephew Massimiliano or for the king of France, as is suggested by a letter written on 13 April 1485 by Duke Gian Galeazzo Sforza to Maffeo Buglio, the Sforza ambassador at the court of the Hungarian king, Matthias Corvinus:
and since we have heard that His Majesty takes great pleasure in fine paintings, particularly those that are of devotional subjects, and given that there is an excellent painter here, whose genius we have had occasion to experience as being without par, we have ordered the said painter to make an image of Our Lady that is as beautiful, excellent and devout as he knows how, sparing no expense and he is currently engaged on the work, and shall do no other until it is finished, when we shall send it as a gift to His Majesty.8
At all events, Leonardo succeeded in selling the painting and undertook to paint another one that would be installed in the chapel only in 1508, over twenty years after the first commission. This accounts for the existence of two almost identical versions of The Virgin of the Rocks. The first to be painted, and certainly the one in which Leonardo himself was most directly involved, is now in the Louvre, Paris [Plate 26]. The second, in which Ambrogio de Predis played a greater role (his brother, Evangelista, had died in 1490), is now at the National Gallery in London [Plate 27].
The first painting shows the Virgin in a rocky landscape as she stretches out her right arm to bring the infant Saint John (whose hands are joined together in prayer) closer to the Holy Child seated at her feet. Mary’s other hand extends into empty space with magnificent perspective foreshortening, as if to underline the solemnity of the moment through that suspended and elegant gesture – an invitation to keep silence that is addressed within and outside the painting. On the right, the scene is closed by an angel whose left arm supports the infant Jesus so that he does not fall into the water flowing just beside the child, while the other hand points to the Baptist, who is slightly turning his head towards viewers, to enchant them with his magnetic gaze and otherworldly beauty. The landscape is barred in the centre by a rock that forms a natural arch, opening to the left and to the right into two aerial perspectives whose luminosity breaks the slightly menacing penumbra that envelops the Virgin. The landscape is painted with a subtlety that makes it a protagonist alongside the figures themselves; and it gave Leonardo an opportunity to give visible form to his observations on the formation of rocks.
Whoever admired the painting at the time and in the place of its execution could see represented, in a wonderful evocation, the many legends that had spread throughout central Italy in the second half of the fifteenth century around the cult of Mary Immaculate. The devout would place themselves under her protection during times of plague, the worst scourge of that period – and indeed the population of Milan was about to be struck by an epidemic of the plague in 1485. The Virgin, who is shown presenting a young cousin to the infant Christ with the typical gesture of medieval presentations, coaxing him forward with her arm and protecting him with her cloak, is the apparition conjured up in the Song of Songs (‘O my dove, in the clefts of the rock, in the covert of the cliff, let me see your face’, 2.14) and indeed nothing could evoke this most popular passage in Christian devotion better than the contrast between the young woman who gently bows her face, as doves sometimes do, and the rugged landscape behind her. It is a contrast that also alludes to the dialectic between a world before grace and the apparition of grace through the immaculate conception of Jesus.
The presence of the angel and of Saint John, who were not frequently included in earlier representations of the Immaculate Conception (although it has been rightly noted that Mino da Fiesole had represented Mary, the infant Christ and Saint John in a bas-relief carved for the Cathedral of Fiesole at the end of the 1470s), can be explained with the help of a popular account in one of the early gospels (James, 17–22), which tells how, on the flight to Egypt, Mary and the baby Jesus met the young Saint John, who lived in a cavern in the wilderness, protected by the angel Uriel. By definition, landscapes with hermits are rugged and inhospitable, and Leonardo’s representation is linked to this iconographical tradition, showing the rocky grotto where Mary found refuge and where the future Baptist lived in solitude. The presence of water in the foreground of the painting, into which Jesus seems almost ready to fall but is held back by Uriel’s caring hand, alludes to the future baptism, and in one of the first paintings on which Leonardo worked Christ and Saint John the Baptist met on the exposed bed of a river.
But the presence of the young Saint John was significant to the Franciscan patrons in other ways too. The first name of Saint Francis was Giovanni [John], and the Baptist was particularly dear to the saint from Assisi. The rocky landscape also alluded to Saint Francis because it was among the rocks of La Verna, the Umbrian mountain close to Assisi, that Saint Francis received the stigmata that brought him closer to Christ. The allusive motifs of the surroundings were therefore extremely important for the story that Leonardo wanted to tell, because the altarpiece was intended to be not only a static representation but also a story; it captured and stopped the image of an event unfolding before our eyes, as is underlined by the gaze of the angel, who looks out towards the viewer with his index finger pointing towards the young Saint John.
The other inanimate presences also add to the celebration of the virtues of the Virgin Mary Immaculate at the centre of the painting. The water behind Mary is the water invoked by the early Marian exegetes, who linked her name to that of the sea; and thus, just as all rivers flow into the sea, so all grace meets in Mary, whom the preachers evoked as ‘a vein of the purest water’. Other allusions to the Virgin’s grace and to her story have been highlighted – with varying degrees of success – by the scholars who have interpreted the painting. The palms on Mary’s right recall an exotic setting (Egypt) but also Mary’s glory, while the lance-shaped leaves of the irises by Saint John’s feet allude to the daggers that would pierce the Virgin’s heart at the time of the crucifixion. This interpretation of The Virgin of the Rocks as ‘the Virgin of Sorrows’ has been argued by authoritative theologians and scholars, but the context for which the panel was intended leaves little doubt that Leonardo wished to show an episode in the life of the Virgin Immaculate and that this interpretation would be evident to his patrons and to others who saw the painting.
These devotional aspects of the painting, designed to meet the patrons’ requirements, were set out in considerable detail in the contract drawn up in 1483, but they only partially reflect Leonardo’s interests. His attention and his greatest efforts were concentrated not so much on what had to be shown as on how to show it, and it was here that the artist’s interests become clear, focused as they were at the time on natural sciences and, above all, on the theory of shadows, starting with his studies on optics and the propagation of light.
Turning to the scientific significance of the painting, it has been widely emphasized that the depiction of the rocks corresponds to an exposition of Leonardo’s theories on how mountains were formed and on the life itself of the earth, which, as he wrote in his notebooks during these same years, he associated with that of the human body, where the rivers were the veins and the rocks were the bones. Using painting to anticipate, as usual, results that he would reach through a more systematic analysis in his codices, in The Virgin of the Rocks Leonardo notes with painstaking care his views on the transformation of rocks and his theories concerning their formation. The grotto that serves as meeting place between the Virgin, the Holy Child and the young Saint John is a catalogue of the most complex rocky formations,
produced by the intrusion of an extremely hard igneous rock, diabase, into a soft layer of sandstone, one of the most commonplace sedimentary rocks. Both diabase and sandstone seem to be weathered by atmospheric agents, and Leonardo has precisely shown how the surfaces of the two rock types have been eroded in different ways as a result of their different hardnesses.9
His scrupulous observations of rock structures made during trips to the mountains around Milan allowed him to paint the precise rounded formation left by erosion in the soft sandstone, in contrast to the sharp splinters of the hard diabase. And, as if that were not enough, even the plants growing among the rocks conform to the precise laws of biology that Leonardo had observed and understood. At the lower left-hand corner, beside the pool of water, he painted a yellow iris (Iris pseudacorus), which grows close to water, even if he has given the lower part of its lanceolate leaves a spiral form. Much further from the water he painted a palm (genus Raphis) that grows in dry conditions. The other plants identified by scholars all have a symbolic value, but at the same time, among the various possible symbolic representations, Leonardo chose those plants that conformed to the geological nature of the site and to the chosen season (March–April). Thus he replaced the roses, which symbolize the purity of Jesus, with a bunch of primulas (Primula vulgaris), and again beside the child, he painted anemones (Anemone hortensis), which traditionally flowered on Mount Calvary under the Cross, where drops of blood fell from Christ’s wounds. Nor could the millenary symbol of the resurrection be left out of the painting: that is the acanthus plant (Acanthus mollis), which grows in abundance under Saint John’s feet. Lastly, to reinforce the allusion to the image of Mary as a dove among the rocks, Leonardo paints a prominent and well-lit clump of aquilegia (Aquilegia vulgaris), commonly known as ‘columbine’, as a reference to the previously mentioned passage from the Song of Songs.
Of course, it was not Leonardo’s botanical and geological expertise that made the painting so astonishing that its value went up by over a half. Whoever saw the panel in the artist’s studio around 1490 would have had the impression of encountering something that had not been seen before, in Italy or anywhere else: the beauty of the faces, certainly – the Virgin was almost an angel herself, given her youth – the regular physiognomy of the oval but sweet and rounded face, the three-quarters pose of the beautiful Uriel, from whose pointed finger one might almost expect a ray of light to suddenly emerge; the golden hair of both, with even curls that frame the face in pure light, so soft and radiant is its colour. Such naturalness had never been seen before in the positions of Jesus and Saint John, two infants, little over a year old, whose arms and legs still had that chubbiness that was so prized by parents and pedagogues at the time.
Another element that had never been seen before was the light, which presented the scene in the painting in an entirely new manner. Here there is no sharp contrast between shadows and lights and it is always difficult to see the line between them. A clearly defined border must never be perceptible between light and shade because this gives the image a wooden – today we might say calligraphic – appearance, which was a characteristic of almost all the paintings of contemporary Florentines. Here the transitions between light and shade are perfectly softened thanks to a refined pictorial technique. But it was not merely an extraordinary manual talent that made these transitions so beautiful. Underlying this talent was Leonardo’s theory of optics, which enabled him to understand that the body reflects light in its own way and that, even in areas in shadow, there are secondary lights that round out the volumes, making them visible. This happens especially if, instead of the midday hours, when the light is strongest, especially outside, one chooses to study the models or make them pose in late afternoon, when the light starts to soften, and in an enclosed courtyard permeated by reverberations. In that atmosphere faces look more beautiful, the physiognomic contrasts are mellowed, and no one looks ugly or cross. Light pervades the painting and guides the eye first to the figures and then, after the dark caesura of the rock skilfully placed behind Mary’s pyramidal outline, it bursts out again in those two wide clefts that lead to a far-off sea, where the snow-covered rocks vanish into the atmospheric mists. On the other side, the view into the grotto places a rocky pillar at the centre around which the light revolves, deepening the penumbra that plumbs the depth of the cavern.
It was a theory that turned into practice under the astonished eyes of the Milanese, rich and poor, lay and devout. But this theory of shadows involved a new and revolutionary theory of colours. Leonardo had noticed that colours do not exist alone but only in relation to light, and that it was only in full light that colour reached its fullest tonal saturation, while its tone faded in shade and the stronger the shade the less bright the colour became. The theory of tonal painting overturned the late fifteenth-century techniques, which were operating through abstract juxtapositions: a red mantle was always red, regardless of whether it was in light or in shadow, and in the latter case it would be covered with a light layer of black or brown: ‘The quality of colours will be ascertained by means of light and it is to be judged that where there is more light the true quality of the illuminated colour will be seen.’10
In an attempt to explain his discovery, Leonardo defines it as a chromatic perspective, because colours fade according to the intensity of shadow just as, in a composition in perspective, heights diminish in proportion to drawing closer to the vanishing point on the horizon. These principles were based on Leonardo’s experience and did not by themselves guarantee the success of the painting, because, as usual, it is impossible to distinguish between the role played by science and that played by art in the artist’s work. Certainly in art he reached heights that were entirely satisfying, and it is difficult not to suspect that, merely by organizing the results he had achieved through his pictorial sensitivity, Leonardo derived the optic principles that he then attempted to order into analytical theories in his writings. The sense of an airy, soft atmosphere that pervades the scene is the result of his visual sensitivity; light, shadows and colours can be studied in depth, but they will not guarantee the result achieved in the painting. If Leonardo had had access to a realistic set such as the one seen here and if, paradoxically, he had been able to re-create the light of the painting, the results would have been very different.
Although mentally the artist needed to order his sensations and to convince himself that he was following a rational theory that he had just discovered, in reality he was moved by the pure strength of his imagination. The perfect choreography of Mary’s foreshortened left hand and the unusual length of Uriel’s right hand, as well as their protective gestures towards Saint John and the infant Jesus respectively, form a commedia of emotions that moves the viewer owing to its perfectly calibrated gestures. The same can be said of the intervention of the openings in the rock, which only the artist could have imagined: they are small enough to distract the viewer’s eye towards the light while redirecting it back again and again towards the Virgin’s face.
It is no coincidence that, beyond all theories of light and colour tonalities, the preparatory drawings that have survived from Leonardo assure us that his creative impetus focused precisely on the perfection of these gestures. For example, the Windsor drawing [Plate 28] shows the study of Uriel’s gesture refined to perfection. The sublime elegance of this gesture can only be grasped from the drawing. It is worth dwelling on the actual pictorial method through which Leonardo achieved such exceptional results of form. While The Virgin of the Rocks in the Louvre has not yet been subjected to a detailed analysis through the new diagnostic techniques, its ‘twin’ in the National Gallery has been, and the results can certainly be extended to it, since it is unthinkable that Leonardo would have changed his pictorial technique within the space of a few years.
Judging from what we know of Leonardo’s procedure at this time, he prepared the poplar planks using a coat of smoothed plaster and glue, onto which he then transferred the drawing from the preparatory cartoon for the first time; then he went over it with a brush dipped in black pigment. In this phase he had good control of the composition and could check the suitability of the poses, gestures and proportions. Immediately after this, Leonardo covered the entire panel with an imprimitura, namely a greyish, transparent priming layer composed of oil, lead white and charcoal pigment. This had the dual aim of saturating the plaster and glue and rendering them impermeable, so that subsequent coats of oil paint were not patchily absorbed; at the same time, although the preparatory drawing was partly obscured, it was sufficiently visible and could be retraced with a second preparatory drawing, or even changed if necessary. At this stage the artist retraced the preparatory outline in a darker and heavier medium and then applied a second imprimitura, which also contained yellow, in order to create a base that gave a uniform tone to the painting and contributed to its final unity of colour. On this second, coloured priming layer, which was essential for defining the overall chromatic result, the preparatory drawing was, again, retraced using brushstrokes of heavier paint that, in the case of The Virgin of the Rocks in the National Gallery, contain yellow, natural earth, brown and black.
The study of the shadows started at this stage and contributed to the progress of the actual painting itself. Since Leonardo was aiming for a final tonal unity, one that softened the contrasts between colours, achieving expressive relief even in monochrome helped the subsequent phase of colouring, which would be limited to very transparent glazes; in substance, these velature coloured lightly both the shadows and the highlights, which had already been finalized using the yellow and black oil monochrome, so at this point the volumes were fully defined. It would be more accurate to talk of a monochrome painting than of a second preparatory drawing, which the artist used to finalize the image. This was the base on which Leonardo then proceeded to paint, using the actual colours, diluted either in linseed oil or in walnut oil, depending on his need for various densities of medium and for drying times that varied accordingly.11
These tests have revealed the extraordinary simplicity of the chromatic blends used by the painter. Given that the relief and, in essence, the image were already defined though the monochrome preparation, complete with an accurate study of the transition from light to dark, the colour velature are extremely simple and are applied in a few transparent layers. The sky, for instance, consists of an initial layer of lead white and azurite that already gives a blue tone, and it is then finished simply with a light glaze of precious lapis lazuli blue. The result of tests on the flesh areas is surprising: they reveal a mix of lead white, a touch of vermillion, red lake and sometimes black in the deepest shadows, or brown earth. These are the pigments used by all painters in central Italy and they show that, contrary to the many suppositions and legends regarding Leonardo’s pictorial technique and his sfumato, he did not have a special technique of painting but simply used the current one in a very special way.
Technically, the true singularity of his painting is the accuracy of the monochrome drawing that he had learned to use in Verrocchio’s workshop and that allowed him to control the entire painting, in terms of the light rather than tone. Leonardo paints with shadow what all the others paint with colour. The outcome of The Virgin of the Rocks, now in the Louvre, was a very new combination of tone and light, one that would harden, as we shall see, in the copy made for the confraternity because in this second painting Leonardo did not put the same commitment and the same degree of presence as he did in the first.