why was davids dontello cast in bronze
It would, as Rocke indicated, be misleading to speak of a “homosexual subculture” in fifteenth-century Florence. Homosexual relations, although proscribed and circumscribed, were nonetheless a pervasive and “centric” mode of behavior, linking individuals normally separated by class and by neighborhood affiliations.
Medici Palace Court
It is worth mentioning that some critics have interpreted certain elements of the statue (feather in Goliath’s helmet, David’s hat) to mean that the figure depicted is not David but the Greek God Hermes (the Roman Mercury). However, all references from the Early Renaissance (1400-90) clearly identify the sculpture as David.
Donatello’s Bronze Statue
The statue stood proudly on a column that was designed by the talented Desiderio da Settignano. It was situated in the middle of the Palazzo Medici’s courtyard, with an inscription that explained the significance of the statue as a highly regarded political monument. While the political significance of the sculpture was accepted, the precise meaning of the inscription has become a debatable topic among scholars.
A number of scholars assume that the statue was originally commissioned by the affluent Cosimo de Medici, although the date of creation is widely disputed and unknown to many. Nevertheless, the sculpture presented the majesty of this noble and young hero that stands proudly with a sword in his hand, as well as the decapitated head of Goliath at his feet.
Perhaps Donatello’s landmark work – and one of the greatest sculptural works of the early Renaissance – was his bronze statue of David. This work signals the return of the nude sculpture in the round figure, and because it was the first such work like this in over a thousand years, it is one of the most important works in the history of western art.
In any case, Donatello’s David is a classic work of Renaissance sculpture, given its Judaeo-Christian subject matter modeled on a classical sculptural type. It was revolutionary for its day – so much so that it did not get copied right away. The idea of the life-sized nude sculpture-in-the-round evidently took some time to sink in and become an acceptable statue type.
The marble David is Donatello’s earliest known important commission, and it is a work closely tied to tradition, giving few signs of the innovative approach to representation that the artist would develop as he matured. Although the positioning of the legs hints at a classical contrapposto, the figure stands in an elegant Gothic sway that surely derives from Lorenzo Ghiberti. The face is curiously blank (that is, if one expects naturalism, but very typical of the International Gothic style), and David seems almost unaware of the head of his vanquished foe that rests between his feet. Some scholars have seen an element of personality – a kind of cockiness – suggested by the twist of the torso and the akimbo placement of the left arm,   but overall the effect of the figure is rather bland. The head of Goliath, lying at David’s feet, “is carved with great assurance and reveals the young sculptor’s genuinely Renaissance interest in an ancient Roman type of mature, bearded head”. 
According to Vasari, the statue stood on a column designed by Desiderio da Settignano in the middle of the courtyard of the Palazzo Medici; an inscription seems to have explained the statue’s significance as a political monument.  A quattrocento manuscript containing the text of the inscription is probably an earlier reference to the statue; unfortunately the manuscript is not dated.  Although a political meaning for the statue is widely accepted, but what that meaning is has been a matter of considerable debate among scholars.