‘Exceptional… unmissable’

    Poor Leonardo da Vinci. What have we done to his reality? Of all the great artistic presences disfigured by modern imaginings, Leonardo has surely been disfigured the most. I am not thinking only of the silly Templar secrets hallucinated for us in the pages of The Da Vinci Code. Long before the dreaded Dan Brown got his hands on him, Leonardo was already an overripe mythical presence. The notoriety of the Mona Lisa is partly to blame. So is the mad-scientist persona prompted by his beautifully puzzling scientific drawings.

    Even the fact that so little of his actual output as a painter remains has served to inflate the Leonardo myth: when the facts are few, the imaginings are many.

    Into this cloudy situation, there strides a show that can make a decent claim to be the most important Leonardo exhibition ever. In my book, that is probably what it is. Leonardo shows are rare, for the insurmountable reason that his output is rare. His few surviving paintings are scattered around the world’s haughtiest museums: the Louvre, the Vatican, the Hermitage. These are not institutions that lend easily or often. In the absence of abundant Leonardo artworks, it has fallen to his notebook clippings to feed the hunger and, in the process, pump more gas into the mad-scientist outline. Reconstructed flying machines. Cardboard tanks. Wooden helicopters. All the other Leonardo exhibitions of my lifetime have had the air of a Blue Peter episode about them. But not this one.

    Somehow, in unhelpful circumstances, the National Gallery has managed to assemble a telling display of Leonardo’s paintings. According to my count, only 17 survive. Of these, the great Last Supper, in Milan, is a wonky fresco that cannot travel. Two are hugely unfinished: the St Jerome and the Adoration of the Magi. And the Mona Lisa is simply too famous ever to leave the Louvre. Which leaves 13 pictures from which to assemble a show. The National Gallery has succeeded in getting its hands on nine of them.

    This focus on his paintings is more than welcome. We should see it, I suggest, as desperately necessary. The mad scientist has had too long at the microphone. This event’s proposition — that all of Leonardo’s many interests should be understood as by-products of his central ambition as a painter — needed saying. Not only did he view himself principally as a painter, he considered painting the finest of all the arts. The first picture here makes exactly this point — in a mysterious and mildly tortuous Leonardo fashion. Painted in Milan in about 1486, it’s a portrait of an anonymous musician in a red cap who holds up a sheet of music with a strangely declarative air, as if insisting the viewer take note of it. The catalogue argues, convincingly, that the painting, Leonardo’s only surviving male portrait, is loaded with symbolic meaning: that in it he is arguing for the supremacy of painting over music. The beauty of the music the young man holds up can only last for as long as the music is played. The painting he appears in, however, will be beautiful for as long as it exists. It’s an argument that appears a tad childish today: my art form is better than your art form. In the Renaissance world, however, these were matters of giddy philosophical significance.

    Although it tackles the misrepresentation of Leonardo’s entire output, the show’s focus is on the years 1482-99, which he spent in Milan working for the infamous Sforza family — butcher-dukes of the Renaissance. Judging by what Leonardo painted for them, the Sforzas also deserve a rethink. It was Ludovico Sforza, nicknamed il Moro, the Moor, because he was so dark and violent, who commissioned the Last Supper. Here, in the superb second room, two exceptionally beautiful Sforza mistresses go mano-a-mano, and the exhibition catches fire.

    Lady with an Ermine, which arrives here from the Czartoryski Palace, in Cracow, is so little seen, it almost constitutes a lost Leonardo. The model, the 15-year-old Cecilia Gallerani, was il Moro’s mistress, famous for her impeccable beauty. The angry ermine she cradles in her arms is probably a personification of il Moro himself: the order of the ermine was among his heraldic honours. Thus, this lovely and ambitious picture can be understood as a double portrait, not only of the gorgeous Cecilia, but also of the fierce il Moro, tamed by her beauty. By having Cecilia turn away from us towards the soft light that falls on her face, Leonardo sets himself the challenge of describing such delicate shadows. Once again, he is declaring the supremacy of painting. And making clear why he embarked on all those meticulous studies of light.

    The other picture in an enticing feminine face-off probably shows Lucrezia Crivelli, a later and older mistress of il Moro’s. Whoever she is, I would happily jump into any of the canals Leonardo designed for Milan should she ever fall into one and need saving. And I can’t even swim. Sitting quietly behind a parapet, with only her delectable head and shoulders on view, La belle ferronière, as she is known, is the possessor of a gaze of extraordinary psychological subtlety. Her thoughts may be 500 years old, but they hunt you down across the room.

    I am aware I am beginning to sound like one of those babbling 19th-century epicureans reduced to spurting purple prose on the subject of the Mona Lisa, but there really is something uniquely enticing about Leonardo’s paintings of women. They don’t merely speak to you across the ages, they manage to tug your love strings, exactly as the poets quoted on the exhibition’s walls insisted they would. And, again, they do so to prove the supremacy of painting. If Leonardo’s ambition in Lady with an Ermine was to challenge nature by perfectly evoking the fall of light on a beautiful face, in La belle ferronière he seeks to probe the feminine mind lurking below.

    These magnificent Renaissance agonisings over the power of painting continue through the exhibition. Each of the six rooms focuses on a particular picture and surrounds it with relevant drawings and works by Leonardo’s followers, all of whom are blown out of the water by the master. He always stands apart because he always gives so much more than is asked of him.

    In the unfinished but mightily anguished St Jerome, lent by the Vatican, the penitent saint, lean and stripped, hits himself in the chest with a rock as he stares up, wild-eyed, at a shadowy mirage of Christ on the cross. What a powerful dollop of guilt, terror and religious agony. Jerome’s wiry old body, beating itself with a rock, seems also to describe a punitive state of mind. And Renaissance moods seem already to be turning into baroque ones.

    The show’s central gallery is devoted to another dramatic face-off, between two versions of the Virgin of the Rocks, one from the Louvre, the other from the National Gallery, united here for the first time. Both feature the Virgin Mary kneeling in a rocky grotto above the infant Christ, St John the Baptist and an angel, an arrangement that seems to cast her in the role of a tender nanny protecting her flock. Considering how similar the two compositions are, the huge difference in their impact is surprising. The Louvre’s picture is dark, smoky, sensuous, a companion in mood and tonality to the Mona Lisa. The National Gallery’s version has recently been cleaned and seems altogether brighter, paler, colder, as if painted on porcelain.

    I expected the two rocky Virgins to hang side by side, but instead they occupy each end of the room, as if wishing to put as much distance as possible between themselves. It’s a situation that creates a sense of gladiatorial combat: the French approach to cleaning versus the British; the sensuous Leonardo versus the rational. I found myself preferring the Louvre’s.

    The French argument that paintings should be allowed to grow old gracefully seems particularly persuasive here. It’s not that facelifts are necessarily a bad thing, just that you always notice them. That said, if it wasn’t for serious face surgery, the show’s final surprise, Leonardo’s newly discovered Christ as Salvator Mundi, would not have been newly discovered. Caked in centuries of pictorial grime, it would have remained another anonymous version. In a cocky move, the National Gallery has dared to include it in this display and shown instant faith in the fresh authorship. What a strange picture: Leonardo’s new-age Christ, holding up a rock crystal sphere to mark his divinity and staring out at us with such eerie stillness. If you wrote “1st” in the corner, you’d have a postage stamp for Christmas.

    Having expected to doubt the surprise new authorship, I found myself fully convinced by it. The rock crystal orb, Christ’s blessing fingers and his curly hair are super-sensitively painted by a hand we now recognise: a hand seeking always to extend the limits of depiction. The sheer strangeness of the image makes it feel Leonardo esque. No normal painter would have attempted this.

    New paintings. New considerations. A new way of seeing Leonardo. This exceptional and unmissable show feels as if it is finally presenting us with a painter we can trust.