The painting in the UNESCO listed church was completed in the 1490s, but damage was already being reported in 1517 and by 1556 it was being described as “ruined” by Giorgio Vasari. A doorway was cut through the wall in 1652, which was later closed with bricks, and in the 1760s a curtain hung to protect the painting only made things worse by trapping moisture on the surface. The first restoration attempt was in 1726 when Michelangelo Belotti filled in missing sections with oil paint before varnishing the whole wall. From then on, restorations only seemed to do more damage. In 1821 an expert in removing frescoes attempted to move the painting - he managed to damage the center of it considerably before realizing it wasn’t a fresco at all and trying to reattach the damaged parts with glue. The painting was lucky to survive World War II - if it weren’t for extensive sandbagging and protective scaffolding then it might have been destroyed along with a substantial part of the rest of the building. The most recent restoration took 21 years, finishing in 1999, and it tried to clean the painting, undo some of the earlier restoration attempts, and repaint some areas. Where possible the team used scientific tests to determine what the original painting was like, and where they couldn’t determine what used to exist in a spot they decided to paint it in muted watercolors rather than invent something. How well this was done and whether the work still looks like the original is a matter of debate among art historians.