The aim is that of investigating organically and correctly, from a scientific point of view, the art of the Macchiaioli (movement that originated in Florence in the mid-19th century), assessing the great importance it had in the European painting of the19th century. Among the various painting movements of the Italian 19th century, that of the Macchiaioli was the movement that contributed the most to the renovation of traditional aesthetics: even though it developed only in Tuscany, it became renowned all over Italy thanks to its original solutions, fundamental in the European realism. Who were the Macchiaioli? A group of young people coming from different regions of Italy, mainly from Tuscany, with a common passion for art, political ideals and a strong patriotism. They were passionate Republicans and followed Mazzini's ideas as well as those of the great theorists of French Socialism, like Saint-Simon and Proudhon ( the latter also wrote books on the social function of art), and many of them took part to the campaigns of liberation from the Austrians. The Macchiaioli, as they were called due to their painting style ( macchia = stain), created an innovative, revolutionary language . The Macchiaioli, overbearing and firm in criticizing their masters, derive their strength and imagination from the lively atmosphere of a liberal, modern Florence, the favourite destination for writers, musicians and philosophers, shelter of politicians, exiled from other Italian Sates, and also stable or temporary residence of rich and cultured strangers.