In 1494, Piero de' Medici promised to help the French, led by Charles VII, occupy the city of Naples, but the French armies also occupied Florence. A month before their arrival, Michelangelo fled, first to Venice, then to Bologna. In Bologna, the already renowned Michelangelo finished commissions for three small sculptural figures for the shrine of San Domenico. After an angry Florentine public drove the Medici leaders from the city and into exile, they declared a republic. Forces from the city of Mantua repulsed the French in 1495, and Michelangelo returned to Florence in 1495, where he was commissioned by a lesser member of the Medicis to sculpt a figure of St. John the Baptist. In 1496, Michelangelo completed a commission for a Cupid figure that was fraudulently sold by a dealer as an antique, to Michelangelo's outrage.
Angered by the incident involving the Cupid figure, Michelangelo left for Rome in the summer of 1496. There he met a wealthy banker named Jacopo Galli, who commissioned him for a drunken Bacchus statue that became one of Michelangelo's best-known early works. The statue was an incredibly sensuous piece, and an accomplished work for the twenty-one-year-old artist–a masterpiece in the Classical style that also had moral content and character. Galli also secured a commission for Michelangelo from Cardinal de la Groslaye for a pieta, an early masterpiece of emotional power and detail. Michelangelo brazenly put his signature across the statue's chest, purportedly after an admirer mistook it for another artist's work, and it remains his only signed piece. The statue is of a Virgin Mary sadly contemplating the body of her dead son Jesus Christ, which she holds in her lap. Michelangelo's interest in contrasting and exaggerating figures for emotional effect is already visible in this early work, where the Virgin is disproportionately massive and the dead Christ is diminutive. Michelangelo finished the Pieta in 1499, and he returned to Florence in 1501, having already earned a reputation as a young virtuoso.
In Florence, Michelangelo had no trouble finding work. After completing a figure of Madonna with the Christ Child and beginning another commission which he never completed, Michelangelo received a prestigious contract for a colossal figure of David intended for the outside of the Duomo, the cathedral of Santa Maria del Fiore in Florence. Michelangelo had to work from a marble block already damaged by a previous sculptor, and it took him three years to complete the figure. A masterpiece of taut sensuality and alert courage, the David was a work with which Michelangelo closely identified, and which represented for the Florentines the strength and virtue of their small city-state. The giant statue, with its over-sized hand and feet and its robust, dynamic musculature, is decidedly anti-Classical. The David marks Michelangelo's first major departure from idealized Classical imitation to his own vigorous style and tense understanding of the human form as a prison for the soul. Michelangelo completed the David in 1504, at the age of twenty-five. After it was placed in front of the Duomo, Michelangelo began work on a bronze copy of David, as well as other, smaller projects, including three representations of the Virgin Mary and Child and a preliminary drawing (or "cartoon") of the "Battle of Cascina."
I think the time when the Council of Trent condemned naked pictures was in Session XXV on December 4,1563. The public domain translation of the Council of Trent by Tanner says, "Furthermore, in the invocation of the saints, the veneration of relics, and the sacred use of images .... all lasciviousness avoided, so that images shall not be painted and adorned with a seductive charm"