Because of the experimental methods used by Leonardo, 'The Last Supper' started to deteriorate much sooner than a traditional fresco would have.
'... the Last Supper is now but a shadow of its former self as it would have appeared on completion in 1497. A combination of the unorthodox painting techniques employed by Leonardo, the pervading dampness of the refectory wall and repeated programmes of restoration that began as early as 1517, have all contributed to the substantial deterioration of the painting.
'Leonardo ..chose to seal the stone wall with a layer of pitch (resin) gesso (powdered calcium carbonate) and mastic (from the evergreen shrub), then paint onto the sealing layer with tempera (egg tempera a type of artist's paint)'
If the work was not finished until around 1498, then one assumes that, even if the quality of the finish was not as good as it should have been, it should have been recognisable, at least, for a few years.
Copies were made.
Giampietrino apparently worked with Leonardo and did apparently copy his works ~ and he seems to have been responsible for some early copies of this piece.
Last Supper (copy after Leonardo) c1515-20
'This is one of two large-scale early copies on canvas of Leonardo’s Last Supper, which is almost the width of the original fresco.'
'Nothing is known of its origin, patron, date of execution or intended location. It was first mentioned .. in 1626 ....'
' ... the current attribution to Giampetrino (Giovanni Pietro Rizzoli), who was a talented assistant of Leonardo’s in Milan, is now generally accepted.'
'It is possible that Giampietrino may have assisted Leonardo in painting the original Last Supper in the Refectory of Santa Maria delle Grazie. His copy may provide a record of some of the details now lost in the original fresco ....'http://www.universalleonardo.org/work.php?id=572http://www.universalleonardo.org/worklar...ount=&name=
Giampietrino (notices 1508 — 1521) possibly Giovanni Pietro Rizzoli, (documented from 1495 to 1549), was a north Italian painter of the Lombard school and the Leonardo circle, succinctly characterized by S.J. Freedberg as an "exploiter of Leonardo's repertory."http://en.wikipedia.org/wiki/Giampietrino
It is apparently believed that Giampietrino painted his copies around 1515-20, which is about the time that 'The Last Supper' was described as 'starting to flake'. In the circumstances, maybe he wanted to record them, while they were still in relatively good order. Maybe the fact that Leonardo died around this time is somehow relevant.
'As early as 1517 the painting was starting to flake. By 1556—less than sixty years after it was finished — Leonardo's biographer Giorgio Vasari described the painting as already "ruined" and so deteriorated that the figures were unrecognizable ..'
I cannot find a note of who painted the Tongerlo copy ~ perhaps no-one knows??? ~ or when, but it must have been before 1545, because the abbey claims to have had it in its possession since then, and that is less than fifty years after Leonardo's 'Last Supper' was completed, and a decade before it was deemed 'ruined'.
'By 1556—less than sixty years after it was finished — Leonardo's biographer Giorgio Vasari described the painting as already "ruined" and so deteriorated that the figures were unrecognizable ..'
If we look at Giampietrino's 'The Last Supper' at Magdalen College:
And the Tongerlo 'Last supper': http://members.lycos.nl/guiver/hpbimg/Tongerlo%20laatste%20avondmaal.JPG http://4.bp.blogspot.com/_GzQnzaF4k-o/RbpNPoqNQRI/AAAAAAAABK0/PaFzbAc7qxA/s1600-h/7lastsup++copy.jpg
We find that they are very similar.
Is that because one is a copy of the other, or because they are both copies of Leonardo's original?
And how much have they been altered by restoration over the years?
Can we or can we not say, with some degree of certainty, that these paintings represent something very close to Leonardo's original?
I am no expert, but I do not see why not.
Other copies are considered to be close to the original.
This 'Leda' is considered to be a decent copy of a Leonardo original:http://www.en.utexas.edu/amlit/gifs/leda_vinci.jpg
And this is Giampietrino's version:http://www.lost-leonardo.com/imagz/leda_giam.jpg
What do the faces of 'John ' look like on these copies?
Well, to me, they look like the Madonnas in the 'Virgin of the Rocks' paintings:
“Virgin of the Rocks” by Leonardo da Vinci, displayed in the Louvre, Paris.http://upload.wikimedia.org/wikipedia/commons/f/f5/Virgin_of_the_Rocks.jpg
“Virgin of the Rocks” by Leonardo da Vinci, National Gallery, London.
I have no idea whether or not Leonardo was portraying the beloved disciple as a female, but I wouldn't discount it.
Yes, he painted effeminate-looking young men, but why should the model for beloved disciple look like the model for the virgin Mary?
Anyway, whatever Leonardo thought about the matter, that doesn't mean that he was correct. The Bible does indicate that the 'beloved disciple' was male. However, I have read interpretations where the writer felt that the text may have been manipulated to hide an unsavoury truth. I am hoping to find that.
And, of course, not only can we not rely on a painting that has changed over hundreds of years, but we cannot rely on writings that have changed over thousands of years and which had an agenda in the first place.
It is a truly fascinating subject, but I doubt that we shall ever know the full truth