The Medici family emblem—a number of red balls on a gold shield—is prominently displayed on buildings all over Florence and Tuscany. It’s everywhere and you can’t help but see it as you stroll 
the streets of Florence. One outraged contemporary of Cosimo il Vecchio(the grandfather of Lorenzo the Magnificent)making a rather vulgar pun, declared that "He has emblazoned even the monks' privies with his balls!"
The Medici family crest has long been the object of much historical speculation. The most romantic (and surely mythical) explanation of the origin of the emblem is that the balls are actually dents in a shield, inflicted by the fearsome giant Mugello on one of Charlemagne's knights, Averardo. (The Medici family claimed that they were descendants of this great, and quite likely only legendary, warrior). The knight eventually vanquished the giant and, to mark his victory, Charlemagne permitted Averardo to use the image of the battered shield as his coat of arms.
Other theories suggest that the balls had less exalted origins: that they were pawnbrokers' coins, or medicinal cupping glasses, a medieval remedy, that recalled the family's origins as doctors (medici) or apothecaries. Others say they are bezants, Byzantine coins, inspired by the arms of the Arte del Cambio ( the Guild of Moneychangers, the bankers' organization to which the Medici belonged).
In times of danger, supporters of the Medici were rallied with cries of “Palle! Palle!Palle!” Palle means balls, and this was surely a reference to the balls of the family crest. Whatever the origin of the Medici family emblem, it is interesting to note that the number of palle depicted in it varied. Originally there were 12; in Cosimo de Medici's time it was seven; the ceiling of San Lorenzo's Sagrestia Vecchi has eight; Cosimo I's tomb in the Medici Chapel has five; and Ferdinando I's coat of arms in the Belvedere, six.
One thing is certain, whenever you see this sign, you know that Medici money helped build or finance that building.
