For more than five centuries The Last Supper has been an artistic, religious and cultural icon. The art historian Kenneth Clark called it ''the keystone of European art'', and for a century after its creation it was regarded as nothing less than a miraculous image. And yet there is a very human story behind this artistic ''miracle''. Ross King''s Leonardo and the Last Supper is both a ''biography'' of one of the most famous works of art ever painted and a record of Leonardo da Vinci''s last five years in Milan.
