At the end of the 7th century BC, the Secchia valley represented an important route for the Etruscan trade, present in our area until the arrival of the Gauls in the 4th century BC. Several names, in particular of watercourses, have a clear Gallic origin, for example: Dolo would derive from Dolovius, a Gallic god as well as Lucenta, from the Celtic god Lucientius. Subsequently, the Ligurians overlapped the Gauls, whose political and military supremacy ended with the battles on the Valestra and Bismantova mountains, won by the Romans in 176 BC. The Roman domination was characterized by extensive land reclamation works, which allowed the creation of stable colonies such as Levizzano (Livicianus fund) or Toano (Tullis fund). The territorial and juridical structure was endangered by the barbarian invasions and only after Justinian, having ascended the throne of the surviving Eastern Roman Empire, wanted to reconquer the western territories, a new organization was outlined, with Ravenna, as “Capital branch”, which became the seat of the Exarchate in whose territories were also included our areas belonging to the “Castrum Verabulum”, corresponding approximately to the middle valley of the Secchia and the valleys of the Dolo, the Dragone and the Tresinaro. This valley community was divided into smaller “districts” destined to later become “Pievi”. In 728 our territory also surrendered to the Lombards, starting an irreversible political-military decline from which the juridical-administrative and religious systems were saved; a short time later, in 773, there was the invasion of the Franks who left a certain autonomy to these areas, in which, around 950, the influence of the Canossa family began to feel who in a short time, with wise strategy, put together numerous land properties from the Apennines to the Po ‘.
On 27 June 1094 the Bishop of Reggio, Eriberto, consecrated the first church to the martyrs Saints Ippolito, Cassiano and Floriano. It is a sure dating as it is derived from the inscriptions engraved on the lead box found, in 1957, during the demolition of the main altar of the parish church of San Cassiano, built in place of the now dilapidated one of 1094 and consecrated. on 25 October 1615, while the bell tower, which still exists today, was finished in 1664. After the death of Matilde di Canossa (1115), much of the territory of San Cassiano was purchased by the family of “da Baiso”, vassals of the Canossa, who ceded it to the Fogliani who became undisputed lords of these lands from the mid-1200s and until, at the beginning of the 1400s, the Este family entered the mountain, whose dominions the Municipality of San Cassiano was part of, albeit among alternate vicissitudes, until to the suppression of all administrative structures of the feudal system, which took place with the arrival of Napoleon, in 1796. Following the example of revolutionary France, the territory of the Cispadane Republic was divided into “Departments”, headed by a Prefect, an expression of a local government that provided for the participation in public offices of all citizens. The Department that concerned us directly took the name of “Department of Crostolo” and was divided into 22 “Cantons”: San Cassiano was in that of Carpineti. After various administrative events, the municipal institution was reaffirmed in 1859 and took on the structure we still know today with San Cassiano becoming part of the Municipality of Baiso.