What battle scene did Michelangelo design a cartoon for but never completed?

Michelangelo designed a cartoon for the Battle of Cascina, but never completed the planned fresco.

The commission came from Florence for the Salone dei Cinquecento in the Palazzo Vecchio. The intended decoration was unusually ambitious: Michelangelo was assigned the Battle of Cascina, while Leonardo da Vinci worked on the opposite wall’s Battle of Anghiari. Both projects became famous unfinished episodes in Renaissance art.

Michelangelo’s cartoon showed Florentine soldiers bathing in the Arno when a sudden Pisan attack forced them to scramble for their armor. The scene gave him opportunities to depict numerous twisting, athletic male nudes in different poses—an ideal showcase for his knowledge of anatomy and movement.

He produced a complete preparatory cartoon, but the final wall painting was never made. The cartoon was later damaged and cut into pieces, while copies and related studies helped preserve its composition. The Battle of Anghiari is the common mix-up because it was Leonardo’s paired project, not Michelangelo’s.