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.
Apollo (Michelangelo)
Hallmarks of his style and methods exist on the unfinished work that support the attribution of the statue to Michelangelo. The subject of the unfinished statue was never noted by Michelangelo, however, and contemporary historical sources disagree about the subject. According to Vasari it is an "Apollo", perhaps in the act of taking an arrow from a quiver. In the inventory of Cosimo I of 1553, however, it is identified as, "David", by whoever drew up the historic catalogue. Art critics therefore identify the sculpture as one or the other, or, by showing a hyphenated title, "Apollo-David" or "David-Apollo", to note the uncertainty. Factors favoring the identity as Apollo are: the body is stocky and mature, as Apollo often was portrayed, rather than the typical portrayal of a youthful David; no bow is represented in the carving and, no unfinished portion of the statue allows enough area for one.