Читать книгу The Last Leonardo - Ben Smith Lewis - Страница 14

Mystery is the defining quality of Leonardo’s art. A seductive glance is thrown, we know not to whom. The Virgin and child take shelter with saints and angels in a twilight grotto, which has no address in the Bible. A smile, whose cause can only be imagined, begins to cross a woman’s face, if indeed it is a woman’s face, if indeed it is a smile. Around these strange incidents and encounters hover a few ambiguous facts open to a multitude of interpretations. Our understanding of Leonardo’s life and work rarely becomes more than a pool of theories, surrounded by a tangle of conjecture, suspended from a geometry of clues. Amidst this network of possibilities, the Salvator presents the most fundamental mystery of them all. In some respects, it appears to be the most compressed embodiment of the essence of Leonardo’s art; in other ways it is a stark anomaly. While other of Leonardo’s paintings ask questions like, Am I smiling? or What am I feeling? or even Who is winning?, the Salvator asks Am I a Leonardo?

Leonardo’s paintings have left a trail of documents behind them – contracts for commissions, legal filings from irate clients, eyewitness statements from admirers, oral histories recorded by the children of men who knew him, and even notes in the margins of books on completely different subjects. Such documents are a mine of information.

There are legal agreements for many of Leonardo’s commissions, each of which contains its own set of illuminating details about Leonardo’s profession and character. The one for his first major work, the Adoration of the Magi, offered him a piece of land as payment, which he couldn’t sell for three years, while he had to pay for all the paints and gold leaf himself. He was soon behind schedule, and the monks wrote to him telling him to hurry up. Within a year they had given up, writing off the small sum they had already advanced Leonardo so he could buy wheat and wine. Leonardo was a genius, but also temperamental and, by turns, a self-critical perfectionist: he worked slowly and left many works unfinished, much to the exasperation of his clients. A trail of lawsuits followed him wherever he went.

In 1500 another set of angry monks, this time Milanese, from the Confraternity of Immaculate Conception, refused to pay for the Virgin of the Rocks, now in the National Gallery in London, saying it hadn’t been finished. Leonardo countersued, arguing that the previously agreed fee was too low for the quality of work he was providing. The dispute lasted years. In 1506 a judge ruled in favour of the monks, arguing that there was not enough of Leonardo’s hand in the picture, and that he had to return to Florence and finish it. He went back reluctantly, but it is not known what additional work he carried out on the painting.

Another important client, the Council of Florence, was disappointed the same year, when the artist left for Milan leaving behind him the unfinished Battle of Anghiari, now lost. Leonardo had ‘taken a goodly sum of money and provided a small beginning of a great work, which he should have made’, complained the Gonfaloniere, one of the city’s leaders.

Where there are no surviving contracts, we often read of Leonardo’s paintings in the letters and memoirs of awestruck fans, who recorded for posterity the moment they met the great artist. Secretaries and agents of cardinals and countesses left entries in their diaries marvelling at the paintings and notebooks they had seen when they visited his studio, such as Antonio de Beatis who saw the St John, the Mona Lisa and the Virgin and Child with St Anne in Leonardo’s studio in 1517. Leonardo’s unusual working practices were often a talking point. The Italian author Matteo Bandello recorded watching him working on The Last Supper in 1497:

He would arrive early, climb up on to the scaffolding, and set to work. Sometimes he stayed there from dawn to sunset, never once laying down his brush, forgetting to eat and drink, painting without pause. At other times he would go for two, three or four days without touching his brush, but spending several hours a day in front of the work, his arms folded, examining and criticising the figures to himself. I also saw him, driven by some sudden urge, at midday, when the sun was at its height, leaving the Corte Vecchia, where he was working on his marvellous clay horse, to come straight to Santa Maria delle Grazie, without seeking shade, and clamber up on to the scaffolding, pick up a brush, put in one or two strokes, and then go away again.

Proof of Leonardo’s authorship of paintings can come from the most obscure and unpredictable sources. The identity of the Mona Lisa and the date when Leonardo started painting it were both subject to dispute until 2005, when a German scholar came across a note in the margin of a Renaissance volume of letters by the Roman orator Cicero. The marginalia came from Agostino Vespucci, a Florentine civil servant who worked for Machiavelli. A line from Cicero, about how the fabled Roman painter Apelles left parts of his paintings unfinished, reminded Vespucci of Leonardo. Cicero commented, ‘Apelles perfected the head and bust of his Venus with the most elaborate art, but left the rest of her body roughly rendered …’ Vespucci jotted next to the text:

… This is how Leonardo da Vinci does all his paintings, for example the head of Lisa del Giocondo and of Anne, the mother of the Virgin. We will see what he is going to do in the hall of the Great Council, for which he has just reached an agreement with the Gonfaloniere. October 1503

From such a recent, chance discovery, art historians could confirm that Leonardo was painting a version of the Mona Lisa by 1503, earlier than many had previously thought, and that her identity was definitely the Florentine noblewoman Lisa del Giocondo.

Leonardo’s works were the subject of public spectacle as well as private reflection. By 1500 he was a celebrity, whose every move was watched and gossiped about. It was a major event when a new Leonardo was finished and unveiled to the general public, akin to the opening weekend of a blockbuster film today. Vasari wrote that when a new cartoon of St Anne was put on display in Florence for two days in 1501 (incidentally the first show of a single drawing in the history of Western art), ‘it attracted to the room where it was exhibited a crowd of men and women, young and old, who flocked there as if they were attending a great festival, to gaze in amazement at the marvels he had created’.

There are only two Leonardos that were undocumented in his lifetime: the Portrait of a Musician in the Ambrosiana in Milan, which art historians tend to think is by Leonardo’s assistant Giovanni Antonio Boltraffio, and the St Jerome, whose authenticity has never been questioned and for which certain probable references can be found. Both of these paintings were made relatively early in Leonardo’s career. There is no Leonardo painting executed after 1496 which is not remarked in contemporary sources – except, perhaps, one now.

No records from the artist’s lifetime, or for a further hundred years after it, mention Leonardo painting a Salvator Mundi. This is all the more surprising because of the significance of the subject matter. The Christ which Leonardo painted in his Last Supper is the subject of a long anecdote in Vasari’s Lives of the Artists. He relates how Leonardo went to see his client, the Duke of Milan, and provided a progress report on The Last Supper, explaining that he had still not yet painted Christ’s head because ‘he was unwilling to seek a model on earth and unable to presume that his imagination could conceive of the beauty and celestial grace required of divinity incarnate’.

If the greatest artist of his times was painting the greatest subject in Christian art, a Salvator Mundi, one would expect to find it recorded in a note in a monk’s chronicle or a secretary’s letters, at the very least. The absence of such documentation is the first great mystery of the Salvator Mundi. It compels art historians to rely on their ‘superpower’, ‘the eye’, alone. The name of the artist and the date of execution of this painting can only be determined by analysis of the style, technique and motifs of the work, but the result of such a process will always lack the certainty of proof.

Leonardo never dated any of his paintings, but on stylistic and technical grounds, the Salvator Mundi can be placed in the second half of his career, beginning after 1500 and ending with his death in 1519. The preparatory drawings must have been made in the early years of the sixteenth century because they are executed in Leonardo’s softer red chalk style. They are usually dated 1502–10. The painting itself has the intense sfumato shading of the second phase of Leonardo’s work, beginning in the sixteenth century. The walnut wood used for the panel points to a date after 1506, when Leonardo returned to Milan. Walnut was a relatively unusual choice in Renaissance Florence, but was widely used by Milanese painters. It is difficult to be more precise, because Leonardo worked on many of his pictures for a long time, painting them slowly, sometimes on and off over a decade or more, occasionally returning to them after an intermission, often never finishing them. The scientific means of dating a panel painting by analysing the rings in the wood, dendrochronology, cannot be used with walnut, because the rings are too widely spaced to give more than the vaguest indication of epoch.

Whatever the day was when the first brushstrokes were applied to the Salvator Mundi, Leonardo had by then become one of the most celebrated living artists of the Italian Renaissance, alongside Botticelli, Piero della Francesca, Raphael, Michelangelo, Giovanni Bellini, Andrea Mantegna and a dozen others. He had progressed from artistic child prodigy to gifted studio assistant, then a master painter with his own practice in Florence, and later official court artist, the grandest position a Renaissance artist could rise to in Milan, where he also worked as a sculptor, engineer, set designer and architect. But his career had also had challenging periods when work and money were in short supply.

Born in 1452 in Vinci, a village on the outskirts of Florence, Leonardo was the illegitimate son of a notary, Ser Piero, and a local farmer’s daughter, Caterina di Meo Lippi. His early life was both privileged and disadvantaged. Ser Piero was well-to-do, with a number of properties including a farm in Vinci. By the time Leonardo was in his late teens his father also had offices in the Bargello in Florence, where he offered his legal services to clients from important monasteries and Florentine businesses. But having been born out of wedlock, Leonardo seems not to have received the classical education that a family of Piero’s standing would normally have given their son. He grew up not having learned Latin or Greek, and occasionally referred to that lack in his notebooks. He called himself an ‘unlettered man’, and once signed himself ‘Leonardo da Vinci, disciple of sperentia’, which means both experience and experiment, Renaissance Italian for the ‘school of life’. For the introduction of his planned treatise on painting, which he never published himself, he drafted this opening paragraph:

I am fully aware that my not being a man of letters may cause certain presumptuous people to think that they may with reason blame me, alleging that I am a man without learning. Foolish folk! … They strut about puffed up and pompous, decked out and adorned not with their own labours, but by those of others … They will say that because I have no book learning I cannot properly express what I desire to describe – but they do not know that my subjects require experience rather than the word of others.

Leonardo had the Renaissance version of a chip on his shoulder. He turned this weakness into a strength by approaching his subjects without preconceptions or precepts, making the blank page the starting point for enquiry and creativity.

Fifty kilometres east of Vinci lay the ochre and red assemblage of roofs, domes, towers and crenellations of Florence, where the Renaissance was under construction. The dome of Florence cathedral, designed by Brunelleschi, built without scaffolding out of four million bricks, still the largest masonry dome in the world, was nearing completion; Leonardo was to be involved in its finishing touch, a gleaming bronze ball placed atop the lantern in 1472. Luca della Robbia was filling lunettes and decorating sarcophagi with his ceramic reliefs of pretty Madonnas and characterful saints, smoothly glazed in bright green, blue, white and yellow. In the evenings the low sunlight caught Ghiberti’s Gates of Paradise, a door with ten scenes from the Old Testament, cast in bronze but looking like burnished gold, completed in 1424 and given its popular name by an admiring Michelangelo. It was a beacon to the future of art, with its energetic crowd scenes full of billowing robes and flailing limbs, set within the arches and atria of monumental classical backdrops.

The basic laws of perspective, the representation of three-dimensional space on two dimensions, mostly forgotten since Antiquity, had been revived in frescos decorating chapels by artists Masolino and Masaccio, and in diagrams and text by the architect and humanist Leon Battista Alberti. All these developments were so remarkable that, a century later, they prompted the first ever art history book, Vasari’s Lives of the most Excellent Painters, Sculptors and Architects, to give it its full title. This account of Italian art from the fourteenth to the sixteenth century distinguished between three phases in Renaissance art – early, middle and high – categories which are still widely accepted today. Vasari placed Leonardo at the start of ‘the third manner which we will agree to call the modern’.* Today this period is known as the High Renaissance.

Leonardo’s father was a friend of one of the busiest artists in Florence, Andrea Verrocchio. He ran a large workshop in premises previously occupied by the greatest Florentine Renaissance sculptor from the preceding generation, Donatello, showing how the baton of the Renaissance was handed down from one leading artist to the next. A team of assistants helped Verrocchio execute a mixture of large-scale commissions, statues, jewellery and small workshop paintings, which could be bought by customers coming in off the street. Leonardo had shown early ability with drawing, and his father took him into Florence to see Verrocchio. He was taken on as an apprentice in his mid-teens, around 1469.

Already by his early twenties, Leonardo’s style was so distinctive that art historians argue over which parts of Verrocchio’s paintings might be by the master and which by his precocious pupil. There is a deliciously shiny fish and an alert, fluffy dog in Verrocchio’s Tobias and the Angel (1470–75) which are sometimes attributed to Leonardo. The angel on the far left of Verrocchio’s Baptism of Christ, with his demure and elliptical expression, that tiny knowing smile and hint of gender fluidity, is said to be by Leonardo. In the background, a vast panorama of rolling hills, lakes and steep mountains unfolds, strikingly different from Verrocchio’s well-tended lawns, gentle slopes and neatly pruned trees. Another tell-tale sign is that this background is painted in oil. Leonardo liked to use the new medium of oil paint, which had arrived recently from the Netherlands, while Verrocchio used the old medium of tempera, based on egg yolk, so parts of his paintings finely executed in oils are generally thought to be by Leonardo.

In 1478 Leonardo left Verrocchio’s workshop and set up his own practice in Florence. His first major commission, from an order of Augustinian monks, the Adoration of the Magi, now hangs in the Uffizi. It was a breathtakingly inventive work for its time in how it set aside the conventional, flat depiction of this scene and instead offered a sweeping arabesque of a procession, which curves from the distance to the foreground, suggesting the passage of time and a distance travelled. The wise kings and their entourage gather in a semi-circle around the Madonna and child, evoking a deep foreground space. The recently restored Adoration shows the artist’s underdrawing, a dense web of constantly altered figures, gestures and details, which point to yet another distinctive characteristic of Leonardo: a striving imagination which altered his compositions with a freedom unknown to his contemporaries. The painting was never finished.

In Florence, Leonardo painted a dynamic and beautifully proportioned Annunciation, in which one finds his obsession with naturalistic detail in the flowery lawn and marble table. Close-up photographic study of the painting has also revealed the artist’s fingerprints, another distinguishing feature of his work. Leonardo had, it seems, an idiosyncratic way of occasionally using his fingers and palms to work the paint. At this time he also painted his first known portrait, of Ginevra de’ Benci. The painting’s realism, its glossy oil-painted sheen and austere atmosphere of introspection, show the huge impact on Leonardo of northern European Renaissance painters, whose fame had spread to Italy. In the St Jerome, which never went beyond the design stage, Leonardo conveys the suffering of the saint in the wilderness by his meticulous depiction of an undernourished anatomy. Leonardo’s drawings were as epoch-making as his paintings. On 5 August 1473 he drew in pen and ink what Martin Kemp has described as ‘simply the first dated landscape study in the history of Western art’1 – a view of the Arno valley showing Montelupo Castle, just outside Florence.

Around 1482, Leonardo left Florence to begin the second phase of his professional life in Milan, not for the last time reneging on his contractual obligations to finish paintings when he saw the opportunity for a step up the professional ladder. The new Milanese ruler, Duke Ludovico Sforza, had consolidated his power after defeating the French army and poisoning his nephew. Now, like many a newly established despot before and since, he turned to culture as a tool of statecraft (today this is called ‘art washing’). Sforza wished to make Milan a northern city to rival Florence, but Leonardo appears not to have been aware of the duke’s new priorities. There is a draft of a letter to him in the notebooks in which Leonardo – a man on the make as well as a genius – seeks to reinvent himself as an engineer. He pitches hard that he could make ‘all kinds of mortars, most convenient and easy to carry, and with these I can fling small stones almost resembling a storm’. He could dig tunnels under rivers, make ‘safe and invincible’ chariots, ‘big guns’ and catapults, and lastly – change of subject – ‘I can carry out sculpture in marble, bronze, or clay, and also I can do in painting whatever may be done.’ It was these last two talents that the duke would principally avail himself of.

At the time, Milan was a cultural backwater. The most popular local painters, Vincenzo Foppa, Bernardo Zenale and Ambrogio Bergognone, had barely left the Middle Ages, stylistically speaking. Their workshops were busy but the output uninventive. Thick halos of gold leaf encircled the heads of their saints, who stood stiffly in their heavy robes. Their complexions were pallid and their facial expressions dour and portentous. A wonky perspective in the depiction of a throne, canopy or manger in the foreground usually jarred with that of the architecture or landscape behind. By comparison, Leonardo was the avant-garde with his anatomical and botanical precision, his developing subtle tonality (aka sfumato) and his grip on storytelling.

Leonardo’s first commission in Milan was the most enigmatic painting of his entire oeuvre, the Virgin of the Rocks which now hangs in the Louvre (the National Gallery in London has a second, later version of the painting). Once again the traditional format for such paintings, in which the Virgin and child are seated on a throne on a podium, with saints on either side, has been unceremoniously discarded. Instead, the mother and child appear to have taken refuge in a mountain cave, along with a baby St John, who prays to Jesus, though the Bible never suggests that they met at this age. The group are perched on the edge of a rocky chasm which falls away in front of us, creating a gulf between the viewer and subject. The bizarre landscape of rocky pillars recalls the Surrealist paintings of Max Ernst four and a half centuries later. The painting is the epitome of the sophisticated but indecipherable symbology which Leonardo inserted into his compositions. The lake in the background on the left may symbolise the purity of the Virgin, and so may the foreground, since Mary is referred to in the Song of Songs as ‘the cave in the mountain’. Alternatively, the inhospitable terrain could refer to medieval biographies of St John the Baptist or St Francis, while the manner in which the entire rocky backdrop echoes the arrangement of holy figures could embody the belief, widespread in the Middle Ages and shared by Leonardo, that the earth with its land and water functioned much like the human body with its flesh and blood. Art historians have discussed the meaning of this painting for centuries, without reaching any degree of certainty or agreement.

In Milan, Leonardo introduced emotional transitions, suggested movement and implicit narratives into the static genre of portrait painting. The faces of his sitters show shifting and elusive emotions – moti mentali, as he described them – of acquiescence and resistance, of pleasure and fear. There is a strange atmosphere of serenity and intimacy in these portraits, whose subjects have the faintest of smiles, anticipating the Mona Lisa. The Lady with an Ermine is the most dramatic of them all. A young woman, not yet twenty, turns her head as if taken by surprise – perhaps even feigning surprise – as she hears someone approaching her from behind. She looks shy but inquisitive, demure but also coquettish. The painting was commissioned by the sitter’s lover, the Duke of Milan, Ludovico Sforza. The opposing directions of movement of her head and body belong to the already established Renaissance language of contrapposto, counterpoise, a way of articulating the body to create drama and volume, to which Leonardo has added a narrative purpose.

When Leonardo turned to The Last Supper, a commission for the dining hall of a Milanese convent, he was dealing with an established biblical narrative, in which gestures and facial expressions had long conveyed story and drama. However, he ratcheted up the excitement and action to new levels. He depicted the moment of greatest antagonism, when Christ tells his disciples, ‘One of you will betray me.’ Their reactions create an undulating wave of emotions on either side of Christ – postures and faces showing surprise, shock, denial (from Judas, clutching a bag of money), shame, anxiety, argument, and even fainting. ‘The painter who wants to have honour in his work,’ wrote Leonardo, ‘must always find the imprint of his work in the natural, spontaneous acts of men, born from the strong and sudden revelation of feelings, and from those make brief sketches in his notebook, and then use them for his purpose.’

In the 1490s Leonardo began to write and draw entries in his notebooks, of which only a quarter are estimated to have survived. These codices and manuscripts constitute one of the most important historical archives of all time, a cross-section of the European intellect and imagination at the doorstep of a new world of discovery and experiment, and proof that Leonardo possessed one of the most active and analytical minds of all time, ‘undoubtedly the most curious man who ever lived’, as Kenneth Clark called him.

Across the notebooks’ pages a dazzling array of thoughts unfold about the natural world and the sciences. The art historian Ernst Gombrich remarked how ‘Posterity had to struggle with that awe-inspiring legacy of notes, jottings, drafts, excerpts, and memoranda in which personal trivia alternate with observations on optics, geology, anatomy, the behaviour of wind and water, the mechanics of pulleys and the geometry of intersecting circles, the growth of plants or the statics of buildings, all jostling each other on sheets that may contain sublime drawings, absent-minded doodles, coarse fables, and subtle prose poems.’2 To be sure, Leonardo was as idiosyncratic as he was intelligent: all the text was written in right-to-left mirrored handwriting, which suggests to our imagination a desire to withhold secrets from all but the most dedicated students, but which may also be a sign of Leonardo’s ‘unlettered’ if not obdurate pragmatism. It was easier for the left-handed artist to write backwards because there was less risk of smudging the ink.

Leonardo appears to have been a highly unconventional character. He had a distinctive taste in clothes – his early biographer Anonimo Gaddiano wrote that he ‘wore a rose-coloured cloak, which came only to his knees, although at the time long vestments were the custom’. A list of his clothing in his notebooks itemises a pink cap, two rose-coloured gowns, a purple-velvet hooded cape, and two satin coats, one crimson and one purple again.3 One supposed portrait of him, which may hint at his character, is by his friend Bramante, who, the artist Gian Paolo Lomazzo wrote, used Leonardo’s face for a fresco of the melancholic Greek philosopher Heraclitus. We see a straggly-haired forty-something man, his face running with tears, perhaps from sadness, but also possibly from drunken mirth. Leonardo appears to have been, or to have become, a vegetarian. The Florentine traveller Andrea Corsali wrote a letter to a friend in 1516 in which he mentioned that Leonardo ‘lives on rice, milk and other inanimate foods’. That was a highly unusual diet for a Renaissance European.

Leonardo seems to have had a high sense of self-worth. His pictures did not come cheap by the standards of the day – The Last Supper cost 200 ducats. He could be short-tempered if he felt he was not being accorded the respect he was due: on one occasion he told a client’s cashier haughtily, ‘I am not a penny painter.’ But at the same time he apparently often felt dissatisfied with his achievements, and some early biographers cite that as the reason he left so many of his paintings unfinished. Lomazzo, who spoke to Leonardo’s assistant Francesco Melzi, wrote that ‘He never finished any of the works he commenced because, so sublime was his idea of art, he saw faults even in the things that to others seemed miracles.’

In this first Milanese period, Leonardo was commissioned to make a monument to the Duke of Milan’s father. He designed the largest equestrian statue in the world, and built a clay model three times life-size. But before he could cast it in bronze, the French crown had turned against the Milanese duke. The duke reassigned the metal that had been intended for the statue to the production of cannons, but with little effect. The French King Louis XII invaded northern Italy and occupied Milan. The world lost a masterpiece and Sforza his dukedom. There is a touching description in the notebooks of how Leonardo hid his money in small bags around his studio as the foreign army approached. When they arrived, French archers used Leonardo’s giant clay prototype for target practice and destroyed it.

Leonardo had now lost his great benefactor, and there followed several years of uncertainty, if not poverty. He travelled to Mantua and Venice, reduced on one occasion to making drawings of crystal and amethyst vases for Isabella d’Este, who was considering buying them, and on another to sketching the villa of a Florentine merchant for the Duke of Mantua, who wanted to build his own country mansion.

Leonardo moved on to Florence in 1500, and spent the next six years there. He was given a studio in the large halls of the Santa Maria Novella church. A measure of stability returned, notwithstanding a curious brief interlude in 1502–03 when the notorious warlord Cesare Borgia employed him for two years as his military architect and engineer, although, beyond drawing a map, it is not clear what work the artist actually carried out for the commander.

In Florence Leonardo began his second great phase of works, distinguished by their intense sfumato effects, which included the Mona Lisa and Virgin and Child with St Anne. His storytelling reached its apogee in The Battle of Anghiari, a prestigious commission for the Signoria, the seat of the Florence town council. He had technical problems with this fresco, as would later emerge with The Last Supper. Before he had finished it, his paint started slipping and flaking off the walls of the council chamber. He blamed a freak rainstorm, but the cause was more likely his technique of trying to use oil paint on plaster, to which it could not adhere. Leonardo could be slow at some times, but rushed and careless at others. He could have avoided the decay of his largest works, The Last Supper and The Battle of Anghiari, if he had first tested his technique out on a smaller scale. The original Battle no longer survives, but there is what is thought to be an accurate copy in the form of a large drawing, which probably began life as a copy of Leonardo’s cartoon, which was then reworked or retouched by the great seventeenth-century Dutch painter Rubens – an example of how complicated and how hybrid the authorship of Old Master drawings and paintings can be. The scimitars of mounted soldiers clash, while the heads of their horses butt against each other in a tight, violent circle of a composition which shows that Leonardo, for all his apparent disdain for learning, must have studied Graeco-Roman battle friezes and free-standing sculptures.

In 1506 Leonardo returned to Milan, lured there by its new French rulers, leaving the Battle unfinished, much to the fury of the Florentine town council. In Milan he continued to work on paintings designed or begun in Florence, the Virgin and Child with St Anne and the Madonna of the Yarnwinder among them, although the latter may have been partly executed by assistants. Here he and his assistants probably also finished painting the second version of the Virgin of the Rocks.

The Salvator Mundi was probably begun in this period, possibly for a client from the French court. The painting compresses into its modest format a summation of many, but not all, of the techniques, themes and passions of Leonardo’s oeuvre. His Christ is not like the bright and youthful Jesuses of Raphael, or the strong athletic ones of Michelangelo. He seems a level above such mortal and physical attributes. He floats towards the onlooker like a mystical vision. He transcends time, harking back to the images of a blessing Christ that are found in early Christian catacombs and on the mosaic ceilings of Byzantine churches, but upgraded with a Renaissance makeover that is both realist and idealising. The Salvator’s eyes, eroded as they undoubtedly are, seem to look straight through us, with a gaze as piercing as it is ethereal. Christ’s expression hovers, in that Leonardesque way, between a range of contrasting emotions: serene, placid, wise, resigned, resolute, or implacable and unmoved. On the almost imperceptibly upturned corners of Christ’s lips, damaged as they are, is the slightest trace of a smile. The facial typology of the Son of God seems eerily modern, like those of the Nazarenes or Romantic painters, evidence of the realism and originality of Leonardo’s portraiture.

Leonardo is known for the intricate and precise way he painted hair, so different from the patterned and schematic rendering of his Renaissance contemporaries. In the Salvator, Christ’s long curls glisten with highlights of varying intensity as they catch the light. Amidst the best-preserved strands on the right you will find a double helix, a shape that we find in Leonardo’s drawings of coiled ropes, machines and waterfalls. In his notebooks he wrote of the similarities between the way hair fell and water flowed. There were ‘two motions, of which one responds to the weight of the strands of hair and the other to the direction of the curls; thus the water makes turning eddies, which in part respond to the impetus of the principal current, while the other responds to the incidental motion of deflection’.

These curls may also be carnal. Leonardo’s notebooks contain sketches of curly-haired boys, which are often said to be portraits of his teenage assistant and almost certainly his lover, Gian Giacomo Caprotti da Oreno, whom Leonardo nicknamed Salai, or ‘mischievous one’. In April 1476, a week before his twenty-fourth birthday, Leonardo was arrested by the zealous Florentine vice squad, which patrolled the city streets at night. The accusation was of sodomy with a male prostitute, though the artist was acquitted.

Along the edges of Christ’s garment runs filigree embroidery in golden thread, forming a geometric pattern of knots, sparkling like his hair with reflected light. Leonardo was fascinated by knots, in which his passions for mathematics, geometry and art intersected. He copied and owned the knot patterns of artists, and he also invented his own, far more intricate, ones. Prints of his ‘Vincian knots’ were sold across Europe. Vasari remarked how Leonardo would ‘waste his time in drawing knots of cords, made according to an order, that from one end all the rest might follow till the other, so as to fill a round’. In fact, mathematicians from the University of California analysed Leonardo’s knots a few years ago and found that they were made up of several broken strands, not a single one. Where necessary illusion trumped science in Leonardo’s art.4

The hands and the orb provide further evidence of Leonardo’s keen observation, obsession with detail and willingness to replace the tiringly conventional with the marvellously real. The orb held by the Salvator Mundi was commonly depicted in European Renaissance paintings as brass or bronze, sometimes with a cross above it. Sometimes it was painted as a globe of the earth. In some northern European paintings it is transparent, and within it you may see an unforgiving biblical landscape. Leonardo, however, has painted his as a large, solid rock crystal.† Despite the severe damage this part of the Salvator Mundi has suffered, you can see tiny defects in the orb, known as ‘inclusions’, and air bubbles, each exactingly painted with a dark ring of shadow and a dab of white highlight. Leonardo has added more careful highlights around the fingertips, as if lit by ‘lustre’, as he called bounced light, here reflected off the crystal orb.

Meanwhile, the Salvator’s other hand, raised in blessing, displays a balletic grace and solid volume. It is painted with a faultless foreshortening (a kind of perspective for objects and bodies, when seen front-on) so that it seems to project itself out of the picture towards us. Leonardo has added soft trails of lead white paint along the edges of the fingers, in the creases of the palm, and a dab at the bottom of the thumb, suggesting the softest of broken light from the upper left. Equally, veils of shadow of subtly varying darkness are painted on the parts of the hand facing away from the light, like the third knuckles of the bent fingers. The thumb curves inwards – previously rare in paintings of this type – so that the entire gesture forms an elegantly elongated pyramid, a geometric form Leonardo often used for his compositions of figures.

All these elements cohere in the sfumato style in which the painting is executed. While Leonardo’s peers favoured bright colours and strong lines, Leonardo, a maverick within the Renaissance avant-garde, took painting in the opposite direction towards tonality, building up from dark undercoats to light highlights. Raphael, Michelangelo, Perugino, Piero della Francesca and other Renaissance masters painted scenes that were flooded with light. Their saints, temples and porticos have bright hues. They painted lighter colours on first, in general, and then modelled the figures and architecture with darker shades. But Leonardo worked the other way round. The Salvator is painted up from gloomy underlayers of dark vermilion and black paint. Areas of light are built up from this darkness in thin, transparent layers of very carefully graduated oil-based mixtures, known as glazes. Leonardo advised: ‘Paint so that a smoky finish can be seen, rather than contours and profiles that are distinct and crude.’

However, the sfumato which we admire in Leonardo’s paintings today is never only the work of the Renaissance master. Part of the effect derives from the decay of the art. Leonardo’s fresco paintings, The Last Supper and The Battle of Anghiari, fell apart in his own lifetime because he tried to find a way to paint with oils on plaster; the paint did not stick. In other paintings, most famously the Mona Lisa, the colours have faded and the varnishes darkened. Restorers dare not clean the painting, lest the general public not recognise the work of art which emerges from underneath. The St Jerome once had the saint’s head cut out, and it was only glued back in decades later. Of all Leonardo’s paintings, the Salvator is, relative to its size and regarding the most important areas of the work, the most damaged of them all. Leonardo’s paintings often carry the enhanced atmosphere of an ancient ruin, a work of genius placed slightly beyond reach by the ravages of time. The texture itself prompts a spiritual reflection on the transitory nature of material things, combined with an irresolvable yearning for something lost forever.

While we see so many of the above Leonardesque attributes in the Salvator, other notable aspects of the painting are not very Leonardo. The composition, for one thing, is uniquely flat within the artist’s oeuvre. Christ has none of the movement and contrapposto we see in the figures in Leonardo’s other paintings, despite the fact that he had written ‘Always set your figures so that the side to which the head turns is not the side to which the breast faces.’ Rather than reinvent the composition of this traditional subject, Leonardo seems to have produced, for the first and only time in his life, a carbon copy of the static one that scores of other early Renaissance artists used. The typology of the Salvator Christ, with its long nose and sombre expression, is remote from the delicate, androgynous charm of the Christ he painted in The Last Supper and of a drawing of Christ he made around 1494. In fact, the facial features don’t resemble any of Leonardo’s drawings of other young men. The orb presents another problem. Its realism is undermined by the absence of any notable optical distortions in the drapery behind it, and of the reflections of the surroundings which would logically be visible in such a piece of crystal. Leonardo studied and wrote about optics at length in his notebooks; it is unlikely that he would paint such an object in such an unrealistic way.

After Martin Kemp accepted Robert Simon’s invitation to examine and research the Salvator Mundi, the Oxford art historian embarked on years of study of the painting in all its aspects, from its style to its iconography, and from its overall effect to its smallest details. The painting merits attribution to Leonardo, Kemp has elegantly written, because of

… the soft skin over the bony joints of the fingers of Christ’s right hand, implying but not describing anatomical structure; the illuminated tips of the fingers of his left hand, the glistening filaments of vortex hair, above all on the right as we look at the picture; the teasing ambiguity of his facial features, the gaze assertively direct but removed from explicitness; the intricately secure geometry of the angular interlace in the neckline and cross-bands of his costume; the gleaming crystal ellipse on the pendant plaque below his neckline; the fine rivulets of gathered cloth on his chest.5

The painting has, in short, ‘Leonardo’s magic’. Kemp finds great significance in the contrasting ways in which the face and hand were painted, the former softly, the latter crisply. Leonardo was the first artist to write about aerial perspective – the way colours and outlines fade the further away they are.‡ Kemp notes that the way the blessing hand comes forward in sharp focus towards the onlooker, while the face hovers in a mist of sfumato, is an application by the artist of his observations on the ‘perspective of disappearance’.

Kemp views the painting as Leonardo’s spiritual manifesto. The sign of this is the replacement of the conventional brass orb plus cross (the globus cruciger), with a transparent globe. Through this adaptation Leonardo was representing the cosmology of the Graeco-Roman mathematician and astronomer Ptolemy, who believed that the earth was surrounded by a transparent ‘crystalline sphere of the heavens’, in which the stars were situated. ‘So what you’ve got in the Salvator Mundi is really a Saviour of the cosmos, and this is a very Leonardesque transformation,’ Kemp has said.6

In regard to some of the un-Leonardo-like aspects of the picture, Kemp has developed explanations. The flat composition can be understood as the influence of the Veil of Veronica, an image of Christ’s face, not dissimilar to the Turin Shroud, left when the eponymous saint wiped Jesus’s face with a piece of cloth. The subjects of the Salvator Mundi or Christ Pantocrator, which were very popular in Renaissance Europe, always showed Christ flat-on, looking straight towards the viewer. It was a serious subject, Christ as God, which demanded an austere and sombre treatment. If Leonardo’s painting had been made for a client, a conservative format might well have been insisted on. The explanation for the lack of optical distortions in the orb, Kemp suggests, is that Leonardo was making an artistic decision to break a rule in the interests of the overall impact of his painting. Distortions in the orb would be distracting. The artist was exercising the Renaissance virtue of decorum, or propriety.

But there are shortcomings in Kemp’s analysis. Regarding the significance of the orb, there is no evidence that Leonardo was a neo-Platonist, or even understood what the term meant. Certainly his paintings sometimes contain signs and symbols that refer to the name of the sitter or client, but suggestions that he referenced philosophical ideas as he did the names and coats of arms of his aristocratic patrons remain speculative. As for Leonardo’s depth of field, the alleged blurriness of Christ’s face is contradicted by the sharpness of the curls of his hair, which are in the same plane. One excerpt from Leonardo’s notebooks actually tells painters that if they are painting a figure in the distance, ‘do not single out some strands of hair, as the distance nullifies the shine of the hair’. It is a great mystery why a painting by an artist who studied optics, perspective and light with such intensity should contain two glaring optical inconsistencies. But that is not the greatest mystery of all.

For there is one feature of the Salvator Mundi about which neither Martin Kemp nor any other art historians have said anything at all. Perhaps they have dismissed it, or perhaps they haven’t noticed it. This feature is so individualistic that it can neither be associated with Leonardo’s painting nor disassociated from it; it belongs neither to the pictorial traditions of medieval Italy, nor to the symbology of early Christianity, nor to the classicising project of the Renaissance. The Salvator’s garments are of only one colour. In every other Italian Renaissance depiction of Christ he wears red and blue, almost always a red tunic and a blue robe. The Salvator wears only a blue garment, adorned with gold filigree embroidery. For the moment we have no explanation for this. Let us call it the blue clue.7

* Vasari explained why he thought Leonardo belonged to the third phase of the Renaissance: ‘In addition to the power and boldness of his drawing, not to mention the precision with which he copied the most minute details of nature exactly as they are, he displayed perfect rule, improved order, correct proportion, just design, and a most divine grace.’

† He probably saw rock crystal orbs of this transparency and size in Milan in the early sixteenth century. There is a large one in a museum in Dresden which was made in Milan in the 1570s, by which time Milan had become the centre of rock crystal carving in Italy – another reason to date the Salvator Mundi to Leonardo’s second Milanese period.

‡ Leonardo wrote: ‘The nearest objects will be bounded by evident and sharp boundaries against the background, while those more distant will be highly finished but with more smoky boundaries, that is to say more blurred, or we may say less evident.’