This Leonardo fresco painted in a Milan convent dining hall began crumbling & fading during the artist's lifetime
... to 
paint The Last Supper on the back wall of the dining hall inside the... [DOC] [TLE] Last Supper - History [PAR] In 1495, Leonardo Da Vinci began painting the Last Supper on the wall of the 
refectory (dining hall) of Santa Maria delle Grazie in Milan, Italy, and ... the plaster 
dried, precluding any changes during the course of execution.