The theme of the Last Supper is even found in the art of the catacombs such as at Domitilla and St Callixtus and on early sarcophagi, since the event is closely tied to the final hours of Christ’s life and to his Passion and Resurrection. Besides, the Eucharist, which Christ instituted at the Last Supper, is the primary means by which the Christian community is sustained, by word and sacrament.
While Leonardo’s painting draws on different Gospel accounts for details, it is most closely connected with the account in John’s Gospel. Arguably, it presents a visual expression of John’s theology, long before this was articulated in textual studies. This reading of the painting explains the distinctive representation of John in the painting, which has caused puzzlement and was exploited by Dan Brown in the thriller, the Da Vinci Code.
Leonardo’s painting is conventional in a number of ways: Firstly, it was a commission for a convent refectory and Leonardo followed recent models. Such a scene had been painted on the walls of a number of convents and monasteries in and around Florence by artists such as Taddeo Gaddi at Santa Croce, more recently Ghirlandaio at Ognissanti and San Marco and also in Passignano and by del Castagno at Sant Apollonia. Some of these Leonardo would have been familiar with. It also often formed part of narrative cycles of the Life of Christ on walls in fresco such as Giotto’s in Padua as well as in panel paintings such as Duccio’s Maesta. In a refectory context it is as if Christ is present at the head of the community as they gather to eat. Significantly, the moment depicted in these scenes, as in Leonardo’s, is not the institution of the Eucharist, but the betrayal. It is a reminder to the religious community that while the community gathered to eat is in a place where the banquet of the kingdom is foreshadowed, the drama of salvation is still being worked out.
Leonardo’s rendering was also conventional in that he arranged the figures in a line on one side with Christ centrally, rather as if Christ was head of the community, and included several details such as John close to Jesus, with Peter nearby. However, Leonardo approached the treatment of Judas in a different way and introduced a number of other innovations which drew on his gifts for rendering drama and human expression.
His attempts to include details such as John leaning towards Jesus or on his breast, Eucharistic details and to experiment with the position of Judas can be seen in a number of sketches at Windsor and in the Accademia, Venice. The final result is a remarkable painting in which several dramatic incidents are telescoped into one scene, while evoking the grand mystery of the Passion and Resurrection all in one: There are four groups of three apostles which react in consternation and denial at Jesus announcement of betrayal, the irony of their fervent expression of disbelief, when a few hours later all will have deserted him is captured here better than in any other rendering before or since. The figures seem to explode backwards away from Jesus, while he is composed and serene, and indeed most like the Johannine portrait of Jesus in the Passion narrative.
The group of three on the left of Jesus in the painting is the most interesting, consisting of John, Peter and Judas though each group has great drama and composition- the open wide arms of the apostle on the immediate right are an ironic foreshadowing of the cross. In the group of Peter, John and Judas, Leonardo manages to include combine several details such as Judas being sufficiently close for Jesus to hand him the bread and for John to lean towards Peter to hear Peter’s request that he ask Jesus who it is. Peter holds a knife, a reference to the Garden of Gethsemane incident in Matthew and Judas clasps the money bag while he reaches for the bread indicated by Jesus. However, the most interesting detail is John, or the Beloved Disciple. While all the other figures react in consternation he alone has the serenity of Jesus. His youthful, feminine appearance in the painting was what led Dan Brown to conjecture this was Mary Magdalen and to an elaborate theory that the painting contained the coded teaching of an obscure secret society. However, it is the figure of John which is crucial to Leonardo’s vision and to what particularly singles out the painting. All the other apostles look on in consternation at what Christ is saying, in them we see the gap between Christ with what he is about to do for humanity and human incomprehension at the mystery unfolding. In the figure of John, we see the Beloved Disciple who knows what is about to take place, what it means, the serene faith of the believer after the Resurrection. In this sense, Leonardo captures the narrative voice of the Beloved Disciple, the author of John’s Gospel and places in the painting every believer who contemplates the awesome mystery as it unfolds.