1911 Encyclopædia Britannica (1911)
“ The other chief cities of Emilia—Ferrara, Modena, Reggio, Parma, Piacenza—were, on the other hand, independent, and in the period of the communal independence of the individual towns of Italy each of the chief cities of Emilia, whether belonging to Romagna or not, had a history of its own; and, notwithstanding the feuds of Guelphs and Ghibellines, prospered considerably. The study of Roman law, especially at Bologna, acquired great importance. The imperial influence kept the papal power in check. ”
