A privileged source for the study of the church is provided by the records of the many pastoral visits that have documented its state of repair over the centuries. As the building was privately founded, the proprietors have the right of patronage and the burden of maintenance, and so it is important to investigate their personal history as well as that of their estate. A plaque on the façade states that in 1344 Giovanni di Viviano da Saletta founded the church of Savonuzzo and provided it with the means necessary for its upkeep.
We possess only laconic information about the House; but it is probable that the Da Saletta family were invested with the fief of Savonuzzo in return for services tendered within the ambit of the Este court. By building the church of Santa Maria for the "redemption OF his soul", Giovanni da Saletta gave local folk a place of solace and refuge that was both spiritual and material: but his was also a shrewd move as far as the family fortunes were concerned as it resulted in the creation, within the fief, of an initial nucleus of privilege exempt from duties and taxes.
In 1360 Giovanni's son Pietro inherited the fief and the right of patronage over the church: nineteen years later, he restricted the inheritance of his estate to legitimate male heirs only. The deed also carried a clause whereby, in the event of the male line's dying out, half of the inheritance was to be sold and the proceeds distributed in charity, while the female heirs were to receive only usufruct on the remaining half.
The first description of Santa Maria dates from 1434, the year of a pastoral visit made by Bishop Giovanni Tavelli da Tossignano: the church was adorned with three sacred images; the altar was poorly illuminated because there was no window in the apse: the wooden roof leaked at various points; the door had no lock and the windows no catches; finally, the bell tower had no bell. The bishop ordered the patrons to make repairs and to have a window made in the apse; nevertheless, on the following visit, he ascertained that the work had not been carried out.
The neglect sprang from the extinction of the house of Da Saletta; the only surviving family member was a certain Giovanna, who undertook a legal action to oppose the claims made by the bishop of Ferrara and by the order of the Poveri di Cristo. Nevertheless, according to the terms of Pietro's will, Giovanna was obliged to sign the deed that allowed the Poveri di Cristo to alienate the Savonuzzo estate.
But the notary handling the sale pointed out that the lands had another legitimate proprietor. In January 1447 Leonello d'Este had invested his camerlengo Folco da Villalora with the same feudal lands. Villafora's investiture ran counter to the claims of the Poveri di Cristo and a ten-year-long dispute ensued. In the end Folco donated a large sum to the Poveri di Cristo who waived all claims to the fief.
But the settlement made no mention of Santa Maria and the consequent right-duty to its patronage: it was again claimed by the Poveri di Cristo, and neither the Villafora nor their legitimate heirs were ever officially recognized as owners. This uncertainty was to have a negative influence on the state of the building for over two centuries.
In 1570 Ferrara and district was struck by a devastating earthquake; records of a pastoral visit tell us that the apse of Santa Maria was unsafe and that the bishop had ordered it to be repaired, whitewashed, and paved. However, none of this could be done since the church was no longer in receipt of the income established by its founder. In 1649 death took Alfonso, the last Villafora heir: his entire estate was inherited by Carlo Varano, a nephew of the duke of Camerino. Various pastoral visits followed and the Church repeatedly refused to recognize the Varano family's claims to the patronage of Santa Maria and the building fell into disrepair.
The bishop did not recognize this patronage claim until the end of the 17th century, when he enjoined the dukes of Camerino to restore the church. The order was ignored for decades. In 1748, Cardinal Marcello Crescenzi told the Varano to restore the oratory, to whitewash it, and to repair the broken windows on pain of suspension of the right to worship therein. Seven years later the cardinal returned to Santa Maria and found that Alfonso Varano, the new patron, had restructured and redecorated it.
But the death of Alfonso (1788) ushered in more decades of neglect for the church. This brings us to 1851, when Cardinal Vannicelli Casoni discovered that the new patron, Rodolfo Varano, had allowed the oratory to fall into disrepair and that the altarpiece was torn. Seven years later the royal tribunal decreed the sale by auction of the Varano holdings in Savonuzzo, which were sold to the Finzi-Minerbi company.
In the pastoral report of 1892 the denomination of the oratory is in doubt: "Santa Maria di Savonuzzo" became "San Venanzio". Current scholarship suggests that the Varano, since the 18th century, appear to have been devoted to San Venanzio, it is possible that Rodolfo - in the second half of the 19th century - may have replaced the torn altar-piece with an effigy of the family's patron saint, a fact that could have determined the change in the church's denomination.
After the first World War, for almost half a century, the church was used as an agricultural depot. In 1967, the proprietor Alberto Minerbi decided to restore the church and, in 1983, he donated it to the town council of Copparo and to the Ferrariae Decus, the body that since 1905 has been encharged with the safeguarding of Ferrara's monuments. Thanks to the contribution of the government, restoration began in 1989 and was completed in 1993.