As part of Ludovico's extensive programme for the convent of Santa Maria delle Grazie, Leonardo was commissioned some time between 1494 and 1495 to decorate its refectory with a Last Supper on the wall opposite that on which Donato Montofaro had just completed his large, but modest "Crucifixion" fresco in keeping with the intention of the friars to devote the walls to Christ's Passion, from the Last Supper to the Crucifixion. Leonardo was also required to decorate the three sides of the room with festoons, coats of arms and the initials of members of the Sforza family. His starting points for the Last Supper were the recent versions produced by Andrea del Castagno and Domenico Ghirlandaio in Florence. To overcome what he saw as defects in these works, however, he set out to produce a harmonious composition that would portray both the interactions between the Apostles and their individual temperaments. He therefore divided them into four symmetrical groups of three, two on the left of Christ and two on His right. This morphological and dramatic division gives the picture both its extreme clarity and its excellent equilibrium. In addition, its linear perspective results in an architectonic space wherein the natural world is reduced to small landscape inserts in the background, whereas the dominant chord of the scene is struck by human beings through the masterly representation of their psychological traits.
THE PSYCHOLOGICAL FEATURES OF THE CHARACTERS
The moment captured by the painting is that immediately after Christ's dread pronouncement: "Verily, verily, I say unto you that one of you will betray me". That which follows (and which the painting dramatically underscores) is the reaction of the Apostles. We are presented with a chain of actions and reactions, both different and distant, which the artist describes in a unitary manner. All the sources state that he devoted great attention to this feature and the same impression is conveyed by the many drawings that have survived. The starting point is one of the tenets expressed in his Libro di pittura (book of painting) and on one of the preparatory drawings for the "Last Supper": "When you make your figure, think hard about who it is and what you want it to do". This means that the representation of a figure must both take account of its nature, its character, and express, though its posture and movements, its current state of mind. In the "Last Supper", several persons, each with his own nature, are reacting to the same announcement of the betrayal. Incredulity, amazement and fear are the shared emotions expressed differently according to each person's temperament. Leonardo's efforts were thus directed to deciding which psychosomatic type should be assigned to each Apostle in the light of both the accounts in the Gospels, as well as the "Life of the Saints" by the monk Niccolò Malermi and similar early texts. He also checked out his interpretations in the light of his studies of anatomy and physiognomics, and his observation of real people. He knew, for example, that a no-good, shady character such as Judas had a certain physiognomy. He roamed the streets in search of his "prototypes", at times an almost desperate endeavour. Armenini, writing at the end of the 16th century, tells us that he agonised for months before painting the betrayer because he had been unable to find "a natural head that resembled" his basic idea. After thus determining the type of each Apostle, he turned to their reactions and attributed to each one dissimilar gestures and expressions in keeping with the differences in their temperaments.
