Leonardo and the Last Supper

by Ross King

  Individual members of aristocratic families took to adopting their own personal symbols or imprese: pictures of plants, animals, or objects—accompanied by a motto—that were meant to symbolize a person’s virtues. Lorenzo de’ Medici, in honor of his poetic pursuits and in a punning allusion to his forename, took the laurel tree. Lodovico likewise drew heraldic inspiration from his name. His middle name had originally been Maurus, but a childhood illness prompted his mother to invoke the protection of the Virgin by rechristening him Maria. Yet Lodovico’s eclipsed middle name lived on, forming the basis for endless puns, nicknames, and emblems. Maurus translates as both mulberry and Moor, and Lodovico exulted in both meanings. Mulberries and Moors were symbolically deployed in virtually all of his pageants. His wedding festivities in 1491 had featured a troop of twelve blacked-up Moors parading before a triumphal chariot commanded by the figure of a Moor seated triumphantly on a globe. A consequence of Lodovico’s passion for such imagery was that slaves from Africa became fashionable at the Milanese court, with one chronicler claiming that all Lodovico’s courtiers kept a Moorish slave in their retinue.34

  Leonardo seems not to have devised Moor imagery for Lodovico, but he did compose a sixteen-word literary exercise, a kind of intellectual doodling into which he managed to cram the word “moro” no fewer than five times: “O moro, io moro se con tua moralità non mi amori tanto il vivere m’è amaro” (O Moro, I shall die if with your goodness you will not love me, so bitter will my existence be).35 Leonardo enjoyed this sort of wordplay, which he often combined with riddle-like drawings. While at Lodovico’s court he drew a series of pictographs, or images that worked as rebuses, or clever visual puns.36 Puns of this sort discreetly featured in some of his paintings, as for example in his portrait of Ginevra de’ Benci, where a juniper (ginepro) stands in the background as a visual play on the young woman’s first name.

  There seems to have been an entire industry designing emblems and slogans in Milan, and in the spring of 1495 Lodovico undoubtedly took more than his usual interest in heraldry. For, having been officially invested by Maximilian with the dukedom, he was at last able to add the imperial eagles to his coat of arms. Moreover, he wanted his new coat of arms to appear above Leonardo’s painting in Santa Maria delle Grazie. The convent was already in the process of being covered with Sforza insignia, marking it out as an institution specially patronized by Lodovico. The exterior wall featured terra-cotta shields on which various of his devices, such as the Visconti vipers, were proudly displayed. Adorning the outside wall of the apse designed by Bramante was another Sforza emblem, a pair of hands wielding an axe to chop a log: a reference to Muzio Attendolo’s brief career as a woodcutter.

  On the north wall of the refectory, immediately beneath the ceiling vaults, were three crescent-shaped spaces; here Lodovico instructed Leonardo to paint—as symbols of dynastic authority—three heraldic shields. These three coats of arms, those of himself and his two young sons, were probably the first things that Leonardo painted in the refectory. Their existence is yet more evidence that Lodovico was indeed the man who commissioned Leonardo to paint the mural—and that the mural was meant to be, among other things, a celebration of the ducal family and yet another example of Sforza propaganda.

  After doing numerous designs and compositional sketches for the mural, Leonardo probably began his actual painting in the refectory—on these three lunettes—around the time of Lodovico’s official investiture. There was, however, a sudden irony to these emblems, since the House of Sforza, within days of the investiture, faced a deadly threat to its existence.

  At the end of May, Louis of Orléans, pretender to Lodovico’s dukedom, advanced into Milanese territory from his base in Asti. He was at the head of an army of seventy-five hundred men, “as fine a body of troops...as ever were seen in the field.”37 What followed was a triumph even greater than Louis could have imagined. When his soldiers appeared before the walls of the city of Novara, the citizens promptly opened their gates and received their invaders, according to one account, “with all imaginable demonstrations of joy.”38 This most dangerous enemy, at the head of a strong army and welcomed by Lodovico’s own subjects, was now only twenty-five miles west of Milan.

  Lodovico should have been able to count on help from allies such as the Venetians. By attacking a Milanese possession, Louis risked the wrath of the Holy League. However, Lodovico feared more than the duke of Orléans. He was badly shaken by the actions of the people of Novara. Their loyalty to Lodovico had clearly been eroded by the high taxes and loans they were forced to pay for his extravagant building projects, the huge dowry lavished on the emperor, and the loans and payments to Lodovico’s various allies. Dissatisfaction with Lodovico’s rule was quickly spreading across the duchy. The people of Pavia—a city second in importance only to Milan—appealed to the duke of Orléans to enter their city and deliver them from Lodovico. Meanwhile, if Louis chose to enter Milan, wrote one observer, “he would have been received with more joy.”39

  Fear that his own subjects were turning against him caused Lodovico to panic. He immediately left his country home at Vigevano, where he had been prolonging his celebrations, and returned to Milan. In terror of insurrection and reprisals, he locked himself away in the Castello, refusing to see anyone. He even seems to have suffered a stroke. Two friars reported back to their convent in Venice: “He is in bad health, with one hand paralyzed, they say, and is hated by all the people, and fears they will rise against him.”40

  As Lodovico cowered in the Castello, Louis swung south with his army, advancing on the Milanese army’s camp at Vigevano. The Milanese soldiers were commanded by a captain loyal to Lodovico, his cousin Galeazzo Sanseverino. However, as Louis’s army approached, Sanseverino and his men began preparing for a rapid evacuation. The loss of Vigevano, his birthplace and favorite retreat, would have been a humiliating blow to Lodovico. But Louis evidently determined that discretion was the better part of valor. Rather than attacking Vigevano, he led his forces back toward Novara. At Trecate he was met by some of the “chief citizens of Milan” who urged him to invade their city. Offering their children as hostages to Louis as tokens of their faith and allegiance, they assured him that he would meet with success in the enterprise. The people of Milan, they declared, both the common people and the nobility alike, “desired the destruction of the house of Sforza.”41

  The duke of Orléans’s attack on Novara had been well-timed. He knew Lodovico would be unable to count for immediate assistance on the forty-thousand-strong army of the Holy League. Francesco Gonzaga was moving south to intercept Charles VIII and his army, which had reached a point seventy-five miles southeast of Milan. The French king had managed to cross the Apennines with his artillery as well as five thousand mules laden with gold and other booty. However, his army, reduced by desertion and disease to ten thousand men, was not the same one that had swept down the peninsula a few months earlier. Effortless conquerors of so many Italian cities, the French finally looked vulnerable. Barely had Charles descended the mountain passes than his troops were pursued by Gonzaga’s formidable army. “Here I am,” Gonzaga boasted in a letter to his wife, “at the head of the finest army Italy has ever seen, not only to resist, but to exterminate the French.”42 Among Gonzaga’s troops were fifteen hundred stradiots recruited by the Venetians in Albania and Greece: “stout, hardy fellows,” they dressed like Turks, slept with their horses, and used scimitars to chop off the heads of their enemies.43 Savonarola’s prophecy of terrible misfortunes appeared about to be fulfilled.

  Maximilian eventually came to Lodovico’s rescue, dispatching a contingent of Swiss and German soldiers. The Venetian Senate also offered help, sending to Milan several thousand stradiots. Not everyone in Venice wished to see Lodovico successfully defended: one Venetian remarked that the best thing would be for the stradiots to use their scimitars on Lodovico.44 These foreign reinforcements did, however, prove Lodovico’s saviors, forcing Louis and his army to retreat inside the
walls of Novara. Although over in the space of a few weeks, the episode had been disconcerting and ominous. It can have been small consolation to Lodovico that his rescuers were neither his own subjects nor his own army, but rather foreigners from across the Alps and, in the case of the stradiots, the Adriatic.

  A short time later, on 6 July, Francesco Gonzaga intercepted Charles’s army at Fornovo, a dozen miles southwest of Parma. The French forces were drastically outnumbered, while heavy rains rendered their deadly artillery ineffective. Yet at the very moment when Charles’s men were brutally exposed for the kill, the Italian forces, seeking treasure rather than blood, abandoned their formations and made straight for the booty-laden French baggage train. They were quickly followed by the stradiots, who, not wishing to miss their chance at plunder, threw down their scimitars and likewise began rifling the French wagons. Laden with spoils, the Italian forces beat a hasty retreat, hotly pursued by French menservants and grooms who, showing a livelier spirit of valor than their enemies, took up the hatchets with which they chopped firewood and, according to an eyewitness, attacked the looters and “knocked out their brains.”45 Charles lost many of his own possessions in the battle, including his helmet and sword, as well as a trophy of undoubted sentimental value: a book containing nude portraits of the many young ladies who had granted him their favors during his Italian campaign.

  Although the Battle of Fornovo lasted fewer than fifteen minutes, it resulted in horrendous casualties that made it the bloodiest battle fought on Italian soil in two centuries. The Holy League lost three thousand soldiers, while a thousand French lay dead. The bloodbath concluded with the spectacle of French camp followers, “several pimps and wenches,” stripping the dead of their possessions.46 The Holy League claimed victory, and in honor of the occasion Francesco Gonzaga ordered Andrea Mantegna to paint his Madonna of Victory. No one was fooled, however. The ill-disciplined performance of the Italian forces—“the finest army Italy has ever seen”—had been a terrible and embarrassing disgrace. “The palm of victory,” wrote Guicciardini, “was universally accorded to the French.”47 Meanwhile, the armies of both Charles and Louis remained on Italian soil, each within striking distance of Milan.

  CHAPTER 7

  Secret Recipes

  As Leonardo prepared to start his mural in Santa Maria delle Grazie, one of the first things the Dominican friars would have noticed happening in their refectory was the building of a scaffold. To paint the coats of arms of Lodovico Sforza and his two sons on the wall of the refectory, Leonardo needed to construct a system of scaffolding that allowed him to ascend to a height of more than thirty feet.

  This necessity of climbing ladders and working at altitude, often on awkward surfaces, was one of the reasons that a sixteenth-century artists’ handbook declared that fresco was not for “timid painters or irresolute persons.”1 Removed from the conveniences of his studio, the frescoist experienced physical discomfort and even risked a fall. Michelangelo would severely injure his leg in 1541 when he plunged from his scaffold as he frescoed The Last Judgment on the altar wall of the Sistine Chapel (he recovered, he claimed, thanks to self-medicating with Trebbiano wine). Much worse was the fate of Barna da Siena, who plummeted to his death while frescoing a Crucifixion in the Collegiata in San Gimignano.2

  Leonardo was intrigued by the mechanics of scaffolding. A few years later in Florence, according to Vasari, he invented some sort of scissor mechanism for a scaffold: “an ingenious scaffolding that he could raise or lower by drawing it together or extending it.”3 No drawings or descriptions of his scaffold for Santa Maria delle Grazie survive, though presumably it was less sophisticated. However, like all frescoists he would have provided room enough on the platform to accommodate himself and his assistants, and to allow himself to step back from the wall to appraise his work. He would also have needed a scaffold that caused a minimum amount of disruption to the friars, who, after all, needed to eat their meals in the room where he worked.

  Once the scaffold was built, Leonardo would have begun plastering the north wall of the refectory in preparation for painting. The usual method of frescoists was to apply successive layers of lime plaster to a wall or vault, both before and then during their painting. The first coat, the arriccio, was a roughcast that smoothed over irregularities in the masonry. It also needed to be coarse enough (sometimes brick dust was added) to provide an adhesive surface for the smoother final coat, the intonaco, on which the painter worked. These layers of plaster should be laid, stressed a handbook by Andrea Pozzo, by “an expert and active mason.”4 Although Leonardo must have hired a mason, he may have hoped to involve himself in the preparation of the plaster, experimenting with the addition of ingredients such as sawdust, gesso (a mixture of plaster and size), and textile fibers. “One can also use gesso, sawdust, cloth clipping and glue, and make good plaster,” one of his notes reads. “Or else: tow trimmed with blades as at the fulling-mill, gesso and glue. It is good.”5 He was clearly interested in creating a coarse plaster with an adhesive surface. However, the plaster applied to the wall of the refectory was fairly standard, consisting of lime blended with pulverized quartz and local river sand. It was troweled to a thickness of 1.5 to 2 centimeters, with the plaster in the middle of the wall—where Christ and the apostles would feature—slightly coarser in consistency.6

  The friars would inevitably have been inconvenienced as this work began. For several weeks on end, the refectory, which was poorly ventilated, must have had an unpleasant stink. Pozzo observed that the lime in the arriccio “exhales a bad smell,” making it “very injurious to the health.”7 Once it was applied, the artist needed to wait for it to dry, a process that in cool weather might take a month or two. When it finally dried, the second layer, the intonaco, could be added and the painter was ready to start.

  Frescoists worked in a very precise manner. At the start of each working day, the mason troweled the intonaco on to a small patch of wall to which the artist added his pigments before it dried. Pozzo succinctly described the process. “It is called fresco painting,” he wrote, “because the painting must be performed on it while the plaster is still damp; and for this reason, the plaster must not be spread over a larger portion of the surface than can be painted in one day.”8 A fresco was therefore created section by section, day by day, with the painter working swiftly on small fields of wet plaster. As Pozzo pointed out, a fresco needed to be executed “with greater quickness and celerity” than any other type of painting.9

  Frescoists generally did not paint freehand on the wet plaster. One of the keys to fresco was the use of cartoons (from cartone, a heavy paper or pasteboard) to transfer the design to the wall. The cartoon, a full-scale template for the fresco, was created by scaling up the smaller designs, usually via a grid of proportional squares, and transferring them to a master cartoon made (depending on the size of the fresco) from a few to dozens or more pasted-together sheets of paper. This large cartoon, which for Leonardo’s Last Supper would have been almost thirty feet wide, was cut up into smaller sections, which were then attached to the wall immediately after each patch of the intonaco was applied. The design on the cartoon was transferred to the wall in one of two ways: either by using a stylus to trace over the charcoal drawing and leave incisions on the wet plaster, or else by pricking the cartoon with hundreds of pinholes and then striking it with a pounce bag filled with powdered charcoal, leaving a dotted outline on the intonaco. The painter then removed the cartoon and began following either the incisions or the dotted lines.

  Fresco therefore entailed a huge amount of time-consuming preparatory work before the first brushstroke of paint could be laid: designing and building the scaffold, mixing and troweling the plaster, and transferring designs from the cartoons, which were themselves the product of countless preliminary drawings and as many as several hundred sheets of paper (one famous surviving cartoon, Raphael’s for The School of Athens, a twenty-five-foot-wide fresco painted in the Vatican Apartments in about 1510, was m
ade from 195 sheets of glued-together paper).

  Despite Leonardo’s love of challenges, his lack of experience in this difficult medium would have given him pause. Furthermore, this technique of painting—of expeditiously adding pigments and then moving on to an adjacent section—was ill-suited to his manner of working. He was not someone who worked with “quickness and celerity.” The diary kept by Jacopo da Pontormo as he worked in the church of San Lorenzo in Florence gives a good sense of how the frescoist progressed. “On Thursday I painted those two arms,” he recorded. “On Friday I painted the head with the rock below it. On Saturday I did the trunk of the tree, the rock, and the hand. On the 27th I finished the leg... On Tuesday I began the torso... On Thursday I did an arm. On Friday, the other arm. On Saturday, the thigh.”10

  It is difficult to imagine Leonardo working in such piecemeal fashion. He was not someone who finished an arm on Friday and then on Saturday happily moved on to paint the thigh. He preferred to work at a more leisurely pace than fresco required, concerning himself with subtle effects—modulations of color or transitions of light and shade—that fresco’s requisite speed of execution made virtually impossible. His portraits and altarpieces were painted with prodigious deliberation. He manipulated his paint with great care, blending and texturing the pigments. To achieve his unique effects of light and shade, he even dabbed and smeared the wet paint with his fingertips. Fingerprints can still be seen on several of his paintings, such as his portraits of Ginevra de’ Benci and Cecilia Gallerani—evidence of his attempts to soften the women’s features, as well as of the painstaking efforts he made to achieve his extraordinary visual effects.11

  Leonardo’s lack of experience in the medium, as well as its unsuitability for his particular genius, were probably two of the objections behind his frustrated and fragmentary letter to Lodovico protesting about a commission that was “not my art.” However, evidently reconciled to the project, he decided to proceed, typically, in an experimental fashion, albeit not in the time-honored style followed by the legendary painters whose frescoes he would have seen in Florence.