The Battle of Anghiari (Leonardo da Vinci)
In 1504 Leonardo da Vinci was given the commission by gonfaloniere Piero Soderini, a contract signed by Niccolò Machiavelli, to decorate the Hall of Five Hundred. At the same time his rival Michelangelo, who had just finished his "David", was designated the opposite wall. This was the only time that Leonardo da Vinci and Michelangelo worked together on the same project. The painting of Michelangelo depicted an episode from the Battle of Cascina, when a group of bathing soldiers was surprised by the enemy. However Michelangelo did not stay in Florence long enough to complete the project. He was able to finish his cartoon, but only began the painting. He was invited back to Rome in 1505 by the newly appointed Pope Julius II and was commissioned to build the Pope's tomb.
Masculine psychology
Among artists and scientists during the Renaissance, it was the prevailing belief that the study of the male form was in itself a study of God. Michelangelo's "David" is based upon this artistic discipline, which is known as "disegno". Under this discipline, sculpture is considered to be the finest form of art because it mimics divine creation. Because Michelangelo adhered to the concepts of "disegno", he worked under the premise that the image of "David" was already in the block of stone he was working on—in much the same way as the human soul is thought by some to be found within the physical body as concluded by psychoanalytic theory.