We look at how the cup of the Last Supper cast its spell over one of music’s great agnostics.

The ‘Holy Grail’ is a potent and persistent image in Western culture; a metaphor for all that is prized, mysterious and elusive. Once a favoured subject of Pre-Raphaelite painters and writers such as Malory and Tennyson, today it is linked in popular imagination to Monty Python, Indiana Jones and The Da Vinci Code. Yet, behind this modern facade lies a rich and colourful history stretching back to the 12th century.

In about 1190, the Burgundian poet Robert de Boron identified the Grail as the cup of the Last Supper, that tangible reminder of Christ’s continuing presence among his disciples after his death. According to Robert and his sources, Joseph of Arimathea bore the crucified body of Christ to the tomb where, still bleeding, it was washed and the divine blood was caught in the Grail. By the 15th century, the cup had become an object of knightly romance – the Sangrail. Malory’s Le Morte D’Arthur describes the arduous quests undertaken by Knights of the Round Table to find the Sangrail, quests which only three – Galahad (the purest), Bors (the...