Between the third and second centuries B.C. the Romans started their conquest of the Florentine territory, taking advantage of the little fortified town of Fiesole on the hills above. In the first century Caesar Augustus’ soldiers created Florentia, that was to become an important trading and military hub. This is the period when imperial monuments started to appear in Florence, together with streets following a grid plan, which still make up the heart of the city center, around the current Piazza della Repubblica. With the decline of the Roman Empire and the arrival of the barbaric hordes, Florentia was invaded and raided, faced epidemics and became just a little fortified military camp during the Byzantine era. Starting in the High Middle Ages, quick economic and trading growth combined with military superiority, and after difficult and bloody battles, the city obtained a firm political supremacy over Tuscany. The prosperity of Florence was enhanced by the development of the production of various crafts, with the birth of the corporations of the Guilds, and also by great financial power consolidated in the hands of its banks. The harsh rivalry between Guelphs and Ghibellines, emblematic of the factious spirit that has always characterized the city, ended with the victory of the Guelph party when Matilde di Canossa sided with Pope Gregory VII. Thus the Republic of Florence was founded: consuls supported by a city council and a parliament were to rule, giving rise to one of the first examples of democratic civic institutions in Europe. Florence’s supremacy reached its climax in the fifteenth century, thanks to the rise and consolidation of a new ruling class.The fifteenth century belonged to the Medici: thanks to this family Florence became the world capital of the arts, and under their rule painting, sculpture, literature and music flourished. The city assumed the role of a leading cultural center nobody could erase.After the death of the last member of the Medici, Maria Luisa, the "Elettrice Palatina", Florence passed on to the Lorena family. Later came a brief period under Napoleon and the annexation to the Kingdom of Italy. The violence of the contemporary era was visited on Florence many times: the bombings of World War II didn’t spare its historical center, and in 1966 a devastating flood covered the city and caused untold damage to its historical and artistic heritage. In 1993 an aggressive act of the Mafia sent a car bomb against the Pulci Tower, the seat of the Accademia dei Georgofili, destroying it and badly damaging the nearby Uffizi Gallery as well.