In the refectory of the church of Santa Maria delle Grazie, dating back to the 1400's, in Milano, ancient seat of the Tribunal of the Inquisition, one of the greatest masterpieces of art is under guard; l'Ultima Cena or Last Supper by Leonardo da Vinci, done between 1494 and 1497. This piece is the only fresco of Leonardo that has survived. It represents the Last Supper of Jesus Christ, as written in the Bible, where Jesus announces that he will be betrayed by one of his disciples. The Last Supper, is described in all four Gospels of Matthew (26:17-29) Mark (14:12-25) Luke (22:7-23) and John (13:1-30) an is an ideal pictorial representation of the most important event in the Christian doctrine of salvation - the institution of the Eucharist. Depicted by many famous artists throughout the centuries, there are countless copies and reproductions of this painting in homes, places of worship, and museums throughout the world, that which dominates our imagination is surely that of Da Vinci's Painted in oil and tempera on plaster, this work of Leonardo's expressive mastery, has become one of the most widely appreciated masterpieces in the world which began to acquire its unique reputation immediately after it was finished in 1497 and whose prestige has never diminished. The painting has also been subject to much attention due to the number of restorations it has had to face since its completion in the fifteenth century. The most recent restoration lasted twenty years and has been the subject of much controversy. The painting that remains so influential has been frequently referred to as "repainted", not "restored". However, restoration has been an ongoing reality with this masterpiece due to unprecedented manner in which Leonardo painted it. Although restoration may have altered Leonardo's painting to a degree, it has prolonged the life of this painting for future generations to appreciate and view.