He didn't actually complete very much while he was there, though (this was a recurring problem for him which only got worse in later life) -- his contribution over sixteen years was a couple of paintings [including, it must be said, the famous Last Supper, which would rapidly deteriorate after completion] and assistance with various pageants.

His one attempt at something lasting and challenging, a giant bronze statue of his employer's father on a horse, was delayed many times, lying unfinished for years, and finally put to rest by the French invasion. The seventy tons of bronze set aside for it were appropriated for cannons, and the clay model was used as target practice by the victorious French.