Vasari says Michelangelo and Leonardo da Vinci disliked each other “intensely”. But Michelangelo seems to have really studied the older master, hate him or not.
Here is a page of action figures by Leonardo, thought to be ideas for his Battle of Cascina fresco:
And here is a copy of two of the jousting horsemen Michelangelo made at the time he was preparing HIS fresco of the same battle in competition with Leonardo:
Did Michelangelo sneak into Leonardo’s side of the Consiglio Hall and make a quick copy of his fresco while he was out to lunch? Rafael Sanzio did that: he went to look at Michelangelo’s Sistine Chapel paintings while he was away and copied them; and Michelangelo never forgave him for it.
That the one sketch was copied from the other is obvious. Some scholars doubt that the first page of drawings is by the hand of Leonardo—it may itself be a copy. But the source is certainly Leonardo da Vinci. Compare this horse study of his with the right-side horse in the sketches:
And see this same rearing horse of Leonardo’s, though it is very faint in this reproduction, in another study Michelangelo made for his Battle of Cascina fresco:
What happened to these lively scenes—were they ever painted by either artist?
The copies of Leonardo’s spoiled fresco and of Michelangelo’s cartoon which have survived are almost certainly fragmentary. Probably Leonardo did more than this group:
And Michelangelo included other scenes than this:
Group and action figures were new to Michelangelo then. He had sculpted his giant David, the Roman Pietà, and the Bruges Madonna. And he had painted a strange Holy Family with some not-very-active nudes in the background. Now for this big fresco, whose subject was a cavalry skirmish, he needed to paint groups of men in action and he was looking for ways to give each the energy and grandeur of his statues while bringing them all together in one great general sweep. Leonardo did that like no one else. Michelangelo was obviously impressed.
Notice the horses in particular. In the Leonardo battle the horses not only take part, they are the real protagonists. They clash, they behave almost like fighting cats, one even bites the other. Michelangelo liked that. He liked the way everything participated in the violence and savage clash; and he tried to do his own version. He built the battle around the men, not the horses.
But Leonardo’s lightness and liveliness were not his thing: his deep, brooding nature produced another kind of art. Leonardo had the divine ease of Mozart, Michelangelo the heavier, tragic force of Beethoven.
Read here about their great painting contest.