Placing a statue in the central square of political power was also meant as a message addressed to citizens and foreigners indicating who, at the time, the man in power was, and what values he upheld.
Not by chance, one of the first sculptural groups placed in front of Palazzo della Signoria was Judith and Holofernes by Donatello, commissioned by the Medici for the palace in Via Larga (today's Palazzo Medici-Riccardi in Via Cavour), but  placed in the square after the expulsion of the  Medici from Florence, to symbolize the victory of liberty over tyranny.
From there, the Judith was again moved only when, in 1504, the statue of David by Michelangelo, commissioned for the Cathedral, was considered so magnificent as to deserve a place in the square, where it was to represent, once more, the fight for freedom.
Upon the return of the Medici, it was the bold Benvenuto Cellini who offered to realize a statue for Duke Cosimo I worthy of competing with the masterpieces of the past “in su quella sua bella piazza” (“in his fine piazza”).

Cosimo's choice fell on the theme of  Perseus, which Cellini completed in about 10 years (1545-1554), overcoming considerable technical difficulties. The result is a masterpiece of Mannerist art, for the refinement and the lightness of the large figure holding aloft the head of Medusa as a threatening warning to Cosimo's adversaries.

The statue under the Loggia dei Lanzi was later flanked by other masterpieces, first of all the Rape of the Sabine Virgins (1583) by Giambologna that portrays, in a single group, three figures intertwined with exceptional mastery and virtuosity. The spiraling movement of the entwined bodies anticipates the lines of the Baroque.

 However, to admire other masterpieces of sculptural art, one must visit the museums, not just the Gallery of the Academy, where the David in its original version is conserved, along with the splendid groups of the Prisoners, but also the Museum of Palazzo Vecchio, where Donatello's Judith is found; and the Bargello Museum, where the versions of  David realized by Donatello and Verrocchio, the taste for antiquity in the figure of Michelangelo's Bacchus, and the lightness and the elegance of  Giambologna's Mercury can all be admired.