Ravarino has had several names, and the first one to be written down is its own: a parchment of the abbey of Nonantola dated the twenty-seventh of March 1002, in which abbot Rodolfo leases to a certain Alberico, son of the late Gisone da Sala, some land «et in loco Ravarino», for a yearly rent of four good and spendable Lucca denari. But for centuries the documents call this territory Borgo Franco and above all Orto Vecchio — from Curte vecla, the old court — and it was as Orto Vecchio, together with Castel Crescente, that it was constituted a comune. That name runs on until 1511, and its last appearance is inside a man's title: in a contract of that year count Gianfilippo Sertorio calls himself «Rector ecclesiae S. Johannis de Orto veteri de Ravarino». Of the name itself nobody is certain: it may come from rapa, the turnip grown here, or from rava, mud, which is likelier in a plain the Romans drained; for Tiraboschi and Spinelli it would come instead from Rovaria, from the oaks.
On the twenty-first of September 1310, in the middle of the wars between Modena and Bologna, the popular assembly met and decreed the submission of Ravarino to the comune of Bologna; a few years later that jurisdiction was already over. On the twenty-third of April 1333 the territory was declared a noble fief under the name of county of Borgo Franco and Castel Crescente, and John of Bohemia, regent of the empire for his son Charles IV, granted it to his own personal physician, the Modenese Pietro Della Rocca — and with that act the Panaro was turned towards Solara, which changed the map of the place. The Rangoni were buying land here from the early thirteen hundreds, took over the fief, moved out from Modena and gave their house the character of a fortress and of a lordly seat; in 1453 Niccolò Maria Rangoni obtained from duke Borso d'Este the investiture as count, and the family held Ravarino in governo mediato, almost a state of its own inside the Este duchy, until the suppression of the fiefs in September 1796. The oldest document the comune of Ravarino produced in its own name is dated the thirty-first of August 1462: it is mutilated, it is addressed to duke Borso, and it speaks of a certain homo diabolicus who was going about terrorising the territory.