The Medici fortress of Santa Barbara is a military significant example of architecture of the sixteenth century, around the implementation of which intertwine names Nanni Unghero, the Sanmarino and Bernardo Buontalenti. The construction of the Pistoia fortress forms part of the territorial policy of Cosimo I, but its origins are earlier, and date back to the early decades of the fourteenth century, during the rule of the Florentine Republic; this season are still legible elements-as the great central tower with mastio- functions then encased in the Renaissance building. The new fort was begun in 1543 by Cosimo I, by Giovanni d'Alessio Antonio, said Nanni Ungaro, and then continued by another great military engineer of the sixteenth century, Giovanni Battista Bellucci, said Sanmarino, to which should the definition of the internal quadrilateral, with bastioned fronts articulated by struts with the gunner. A few decades later, the same Cosimo I commissioned Bernardo Buontalenti to the expansion of the fortress, who built a great rampart which encloses the old fortress; the addition Buontalenti incorporates planimetric the quadrilateral Nanni Ungano both bind to the city walls and placing the existing fortress on a kind of pedestal, a veritable fortress. From the mid-seventeenth century, the fortress Pistoia will know a slow and gradual decline, to become then a barracks and military prison, resorting finally in the most tragic pages of city life. In 1944, during World War II, there were shot four young Pistoia. The monumental complex of the Fortress of Santa Barbara is one of the places whose stories are most closely linked to the history of the Risorgimento Pistoia. The central tower of the Fortress, which has formed the prison in which they were locked up the Patriots pistoiesi between 1848-1850, preserves graffiti, writings and drawings in charcoal black and red blood made by imprisoned patriots. A plaque commemorates the shooting of Attilio Hawfinches, Pistoia patriot executed by the Austrians on June 29, 1849.