In 1487 he was again resident in Milan as general artificer--using
that term in its widest sense--to Ludovico. Among his various
activities at this period must be mentioned the designs he made for
the cupola of the cathedral at Milan, and the scenery he constructed
for "Il Paradiso," which was written by Bernardo Bellincioni on the
occasion of the marriage of Gian Galeazzo with Isabella of Aragon.
About 1489-1490 he began his celebrated "Treatise on Painting" and
recommenced work on the colossal equestrian statue of Francesco
Sforza, which was doubtless the greatest of all his achievements as a
sculptor. It was, however, never cast in bronze, and was ruthlessly
destroyed by the French bowmen in April 1500, on their occupation of
Milan after the defeat of Ludovico at the battle of Novara. This is
all the more regrettable as no single authentic piece of sculpture
has come down to us from Leonardo's hand, and we can only judge of his
power in this direction from his drawings, and the enthusiastic
praise of his contemporaries.
[Illustration: PLATE V.--COPY OF THE LAST SUPPER