Michelangelo
Michelangelo returned to Florence in 1499. The republic was changing after the fall of its leader, anti-Renaissance priest Girolamo Savonarola, who was executed in 1498, and the rise of the "gonfaloniere" Piero Soderini. Michelangelo was asked by the consuls of the Guild of Wool to complete an unfinished project begun 40 years earlier by Agostino di Duccio: a colossal statue of Carrara marble portraying David as a symbol of Florentine freedom to be placed on the gable of Florence Cathedral. Michelangelo responded by completing his most famous work, the statue of David, in 1504. The masterwork definitively established his prominence as a sculptor of extraordinary technical skill and strength of symbolic imagination. A team of consultants, including Botticelli and Leonardo da Vinci, was called together to decide upon its placement, ultimately the Piazza della Signoria, in front of the Palazzo Vecchio. It now stands in the Academia while a replica occupies its place in the square.
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.