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.
Sebastiano del Piombo
The first result of this collaboration was one of Sebastiano's most important paintings, a "Pietà" in Viterbo. Here the composition is highly unusual for this common subject (which Michelangelo had famously sculpted in 1498–99), with Christ lying across the bottom of the picture space, at the feet of a Virgin looking up to Heaven, so that the two figures do not actually touch. Though no drawing survives, this was Michelangelo's conception, where "an idea of high tragic power is expressed with extreme simplicity in a structure of severe geometric rigour". The back of the panels have large sketches in charcoal that seem to be by both artists. In 1516 he painted a similar subject, the "Lamentation of Jesus" (now Hermitage Museum) using his own composition, and showing his awareness of Raphael's handling of groups of figures.