Michelangelo
With the completion of the "David" came another commission. In early 1504 Leonardo da Vinci had been commissioned to paint "The Battle of Anghiara" in the council chamber of the Palazzo Vecchio, depicting the battle between Florence and Milan in 1440. Michelangelo was then commissioned to paint the "Battle of Cascina". The two paintings are very different: Leonardo depicts soldiers fighting on horseback, while Michelangelo has soldiers being ambushed as they bathe in the river. Neither work was completed and both were lost forever when the chamber was refurbished. Both works were much admired, and copies remain of them, Leonardo's work having been copied by Rubens and Michelangelo's by Bastiano da Sangallo.
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.